Kitchen Project #22: Salted Apple Caramel Bars

Aka "Brown butter buckwheat salted caramel apple bars"


Welcome to another edition of Kitchen Projects. It’s so lovely to have you here.

This week, I’ve taken inspiration from the KP+ ‘What’s cooking April’ thread to create a pretty insane salted caramel apple bar. The full name for today’s recipe is actually ‘brown butter buckwheat salted apple caramel bars’ but that seems a bit OTT when I write it all out. All you need to know is that it is a FLAVOUR BOMB and there are lots of techniques to be learned.

Maybe you’re asking. What’s KP+? Well I’ll tell you! I launched KP+ last month to create a way for you to be able to support Kitchen Projects with a monthly subscription. Although I’m committed to keeping the Sunday newsletter free (pastry knowledge for all), I’ve been loving sharing extra content and recipes with my KP+ subscribers and having pastry chats in the comment sections.

Here’s an overview of what’s coming up on KP+:

  • Monthly ‘What’s Cooking’ thread for May will launch next week. This is a place for us to chat and discuss topics and seasonal baking ideas for May

  • I’ll be launching a baking dilemma thread with an aim for us to solve and discuss each other’s kitchen issues. First topic will be ‘NO LOITERING’ aka ‘What ingredient do you have hanging around in the cupboard that you can never seem to use up?’ Hopefully the KP+ community can come up with some creative solutions for those pesky ingredients that never seem to go away (evaporated milk, guys, help)

  • A lot of you have been asking for details on Japanese baking on this discussion thread. So, I'm very excited to say that in a few weeks, I’ll be releasing a special edition KP where I interview one of my mentors Chef Ayako Watanabe, formerly of Dominique Ansel Tokyo and founder of Tough Cookie Tokyo, all about Japanese baking. I’ll be sharing a special recipe from Ayako herself on KP+, too!

I’m so grateful for everyone that reads the newsletter every week and your support is hugely appreciated. If you’d like to take that a step further then I’d be overjoyed. If you do join me on KP+, you’ll get access to the entire KP+ archive including discussion threads and things like blood orange cheesecake and vanilla ricotta loaf cake recipes, too.

Alright, enough of that. Let’s do this.


Mystery chocolate tasting announcement!

Before we get into today, I’m making a little announcement about the mystery chocolate tasting I’ll be joining on Wednesday 12th May at 7:30pm.

The wonderful Jennifer Earle hosts monthly chocolate tastings and they are a total riot - once you’re signed up, a week before the event you’ll be sent a selection of six incredible handmade chocolates. But here’s the catch - there’s no details on the flavours! So, we will all be tasting them together blind on Zoom and we get to talk chat through them the help of the seriously talented artisan chocolatier who made them. It’s going to be so fun.

Today I get to announce that the chocolatier for the mystery chocolate tasting will be Alasdair Garnsworthy of The Chocolate Society! Which means we are in for a serious treat. For more details and to sign up, click here. Sales close on Thursday so get in while you can. I hope to see you there.

Bringing ideas to life + seasonal transition confusion

When it comes to recipe development, sometimes an idea that begins in the imagination can be a bit hard to bring to life.

Over on the ‘What's cooking’ thread, we’ve been talking about different flours for pastry baking which gives me the perfect opportunity to talk all about the wonder that is buckwheat. Having a bag of buckwheat on hand is highly advisable - throw it into breads (but not too much, as it's gluten-free), cakes or biscuits and see the flavours transform. I like to think of it almost as a seasoning.

Knowing I wanted to explore the gorgeous, nutty profile of buckwheat, I picked a very happy companion: apples (more on that later), which also work well since we’re in a bit of a seasonal transition for fruit right now. 

A bit like British fruit, we’re all in a sort of transition stage right now, too. We’re out of lockdown *just* enough to be able to make plans and have less time for super time-consuming bakes (sorry opera cake, I love you, but I need to see my friends), but things are still at a slow enough pace that having a pot of something puttering away on the stove is still a welcome side project. As well as that, the sun appears to be shining and yet I am still wearing a puffa jacket daily. All a bit confusing, right?

This week’s recipes

In pursuit of this week’s Kitchen Projects that 1) used buckwheat and apples and 2) could easily be slung into a bag ready for arctic park picnics and walks, I decided a take on the apple pie was the way to go - a pie in your pocket sort of thing.

It took me a while to land on the recipe for this week. I just couldn’t make up my mind. I was texting friends to tell them about my intense biscuit fatigue and how I couldn't even enjoy the taste of butter anymore (serious issue). So, instead of making up MY mind, I’m going to pass on the choice to you by sharing a buildable series of recipes with you which showcase ways to build flavour through a few different techniques that you can nail down and have in your pocket for future baking adventures.

  • Level 1: Solo brown butter buckwheat shortbread

    Techniques: Alternative flours, brown butter

    I started with figuring out a formulation for shortbread which, on its own, was insanely delicious. I mixed it all up, cut it into squares and egg washed, and finished with a little demerara. Although it was fabulous on its own, it didn’t feel quite special enough to warrant a whole newsletter. 

  • Level 2: Getting apple butter involved

    Techniques: Alternative flours, brown butter, slow apple caramelisation

    Next, I baked the shortbread with a layer of apple butter sandwiched in between which was glorious! It definitely was ticking the boxes of the whole transportable apple pie thing. But still didn’t feel like I’d achieved my ultimate goal (also my big sister told me it was ‘cereal bar vibes’ - thanks Pippa - and I was suddenly traumatised by memories of a nutri-grain bar addiction I’d had as a teenager) so I decided to take it up a level

  • Level 3: Caramel apple buckwheat shortbread

    Techniques: Alternative flours, brown butter, slow apple caramelisation, dry caramel

    Finally I stepped it up a notch by making a caramel with the apple butter, which I spread all over the biscuit base to achieve a take on a millionaire shortbread style dessert. I was 100% inspired by the Halva shortbread at Ottolenghi, which was developed by their head pastry chef Paulina Bembel, who is just about the most efficient and slick chef I’ve ever had the pleasure to work for and learn from. If you’ve never tried their halva shortbread, then get yourself to an Ottolenghi asap and try it! It’s also in the brilliant ‘Sweet’ baking book, co-authored by one of my other baking heroes Helen Goh.

Alright, let’s run it down

First: Let’s talk brown butter

I was just hanging around, minding my own business when suddenly I realised something shocking: I realised that I have never covered brown butter on Kitchen Projects. EVER. Browning butter is one of those little kitchen tricks that everyone should have up their sleeves - it’s another way of ‘seasoning’ your baking.

No matter what you’re making - from cookies, to cakes to biscuits, brown butter can elevate your food and make people go ‘omg how did you do that’ or ‘give me a second helping, immediately’. It’s basically magic. So, this week, we’re going to remedy this.

Butter is made up of approximately 80%-84% fat, 1%-3% milk proteins and the rest is water. So, when you ‘brown’ butter, what you’re actually doing is browning the milk solids in butter. This always seemed pretty wild to me - all of that flavour from just a puny 1%-2%? Pretty impressive. 

The fancy term for browning is ‘Maillard reaction’, which I first heard whilst watching a Heston TV show back in the day. I’m still not totally convinced of how to pronounce it (kind of like how I still feel anxiety about saying the word croissant, even though I literally have spent years of my professional career making and talking about them). And anyway, in the kitchen, we don’t ever call it that! But it’s useful to think of browning as a ‘reaction’ to understand what’s going on on a molecular level.

Basically, the maillard reaction is a reaction between amino acids (proteins) and sugar. And, in order for it to take place, it needs heat - above 140c, apparently, according to this article. As these two react, flavour compounds are created. The maillard reaction takes place in almost all forms of cooking and is the basis of flavours, each unique because the proteins and sugars reacting are all different.

Let’s be clear though - browning does not = caramelisation. That’s something different. Caramelisation is not a reaction between two compounds. Caramelisation occurs when sugar is heated and doesn’t need anything else to react with. We’ll be covering that later in the newsletter.

Obvious statement alert: cooking is a real multi-sensory activity. I know we’re used to using our sight and taste and touch, but there are a few key pastry skills that properly employ your sense of sound. For me, brown butter is one of them. When in pursuit of the maillard reaction, you first need to get rid of all of that water. 

As you know, when you’re cooking, it’s impossible to get something to brown when it’s wet - it sounds obvious to say, but this is why roasted food tastes different to boiled or poached food. The reactions required to build those toasty flavour compounds just cannot be created.

So, when you make brown butter, the key is to listen! Before the butter can brown, it has to evaporate all of the water. The whole process is pretty noisy until suddenly… it all goes quiet. This is the time to go and look at your pot and start checking the colour. It’s a good ideal during this time to stir and scrape the pan a bit with something that won’t scratch the coating. You need to do this to release the milk solids that are gathering - if you don’t agitate them, they’ll burn really quickly before the butter has reached the desired colour.

But… what is the ideal colour? Here’s a visual check:

Left to right: Butter has melted, solids are slightly brown. Butter is turning darker and solids are dark brown. Butter is hazelnut coloured and solids are very dark.

That really depends on its final use. For cakes, cookies or biscuits, I like to go DARK. The brown butter needs to stand up against the other flavours going in so you can really push it to be as distinct as possible. I also like to leave all the flecks of brown/burnt milk solids in for extra flavour hits. In some kitchens, the chefs prefer to sieve all of this out, but I’m not one of them.

If I’m browning butter to pour over some vegetables, or pasta, I take it off a little bit earlier. Although I want you to be BRAVE when you’re browning butter and push it as far as you feel confident, I will tell you that blackened butter is GROSS. And, I’m not sure why, smells of rotten fish to me. Honestly, I kind of want you to do it so then I can check I’m not going crazy, but also I would never wish that on you. 

Remember, there will be some carry over cooking as once heated up, fat can hold and retain the heat for ages (think about deep fat frying!) so once it’s a deep golden colour, get it off the heat and out of that bloody pan! Otherwise it might go into bitter territories. Remember, you can always heat it back up and brown it more if you need to. That is always an option.

For this recipe, we will need the brown butter to be solid to incorporate properly into the biscuits so make sure you leave enough time to let it cool down:

And, don’t forget that the final weight of brown butter will be about 20%-25% less than the original quantity of butter so always do more than you need. You can always chuck brown butter on some vegetables, or spread it on your morning toast so having more is never an issue.

The downfall of “simple” 

Playing around with flours can be a challenging but rewarding task. Biscuits are the perfect place to start - especially biscuits that are pressed into a tin and popped straight in the oven. You don’t need to worry about gluten, structure or anything like that. You can just reap the benefits of the flavour.

This week, I wanted to figure out a way to elevate a simple bake by getting some lesser used flours involved. And what is more simple than shortbread? The fact that it’s even called shortbread is a good sign - no gluten needed here.

I do feel like I made myself a bit of a knife to fall on. Sometimes the recipes I perceive as ‘simple’ actually drive me the craziest. There’s nowhere to bloody hide! I also got really caught up on what kind of shortbread to make. The French kind (sables, which use egg yolk and some raising agents) are ultra crumbly and tender whilst the scottish style is usually the simple triad of butter, sugar and flour, giving a super short and crunchy texture.

I started by putting the Scottish and French head to head. I fell in love with the tenderness of the sable - the baking powder adds an admirable lightness - but was completely addicted to the crunch and melting texture from the Scottish style. So, the Scots win (this time). Once I’d decided on this basic element, it was time to start mixing things in - enter brown butter, enter buckwheat. I used a fine-milled stoneground version by Court Hayes.

I’m not going to lie. I had real biscuit fatigue after a week of testing these out. Let’s just say I started the week with 2kg of butter and now I have about 750g. I can comfortably say that the difference is living happily on my belly right now. 

Claire Saffitz, pastry wizard, goes one step further with her flours and toasts the hell out of them before using. I haven’t tried this, but I think this is a pretty smart way to produce further Maillard reactions. Since we are browning the butter for this recipe, I decided to leave the deep flavour compound actions to the milk solids.

Buckwheat is one of my favourite go-to add-ins. I think it makes everything taste ultra fancy. I close my eyes and I feel like I’m in Brittany. Butter + salt + buckwheat is basically a shortcut to french flavour and it is divine. One thing I will say about buckwheat though - it isn’t *the most* adorable colour. It is a sort of… metal grey once mixed with other ingredients. Once baked it does come into a golden hue, but I’ll admit the desaturated tone is a bit worrying at first.

It’s worth saying now that buckwheat - if you didn’t know - is naturally gluten free. When I was researching shortbread, a lot of recipes would use a non-gluten containing dry ingredients - like ground rice (adds a slightly gritty texture… in a good way) or cornflour - in their formulations to achieve a shorter texture. Although these are both good options, they have a neutral taste. By using buckwheat, we are both improving the texture and the flavour. Two birds, y’know.

100% buckwheat on top, 50% buckwheat on the bottom

I tried a couple of versions for this week’s KP and started by baking shortbread with brown butter and 100% buckwheat and although it was delicious, I found that I personally preferred the texture when it was used with plain wheat flour. I tried a few combos, from 25% buckwheat all the way up to 75% buckwheat, but decided on 50% in the end for my ideal texture. Coeliacs worry not - the recipe I’m sharing today does work using all buckwheat flour, but you do need to add a little bit of milk to help it bind, since the 100% buckwheat version was not adequately hydrated with just the butter mix, and was still pretty much a fine powder even after I tried to clump it with my hands.

The plain flour/buckwheat combo also resulted in a ridiculously short biscuit - so tender that it crumbles slightly as you pick it up. Even a gentle prod from the finger will see the crumb collapse. It’s insane. Although this might not be the most practical of biscuits, it is so meltingly perfect that I couldn't resist leaving it as is. Even if the crumbs get on your nerves, the flavour rewards are so high that I think you’ll forgive me.

The 100% buckwheat biscuit, baked for the same time, was a bit more crunchy (perhaps thanks to the additional hydration) and has a gorgeous toasted flavour. It was missing the ultra mouth melting texture that the mixed flour batch gave me, but definitely wins on pure flavour points.

How do you like them apple (butters)

We are in a bit of a mid season fruit purgatory at the moment. The brightest pink rhubarb has slipped away and the peaches, strawberries and plums of summer have not quite made it out the gate. Although I did see a very exciting first sighting of British strawberries (April 18th to be exact), the beautiful British berries we are so blessed with in the summer aren’t readily available yet. 

So, I settled on apples, especially since they are BFFs with buckwheat. I was initially worried that they felt a bit autumnal, but actually there are different varieties in peak all through the year (save for June, July and August) making them the perfect mid season fruit to bake with. Apples are so versatile - they’re a happy-go-lucky sort of fruit and can shine in all sorts of preparations. Whether you are grating them into a cake, stewing them into a compote, caramelising them to high heaven or slicing them into beautiful thin strips to decorate a tart, they always seem pretty chill.

One of my favourite things ever to make with apples is apple butter. I was first introduced to apple butter by Chef Karys, who was the executive pastry chef for the Dominique Ansel Kitchen in New York when I worked there years ago. Karys, who I think I’ve mentioned before on this newsletter, is a total enigmatic pastry genius and one of my biggest inspirations full stop. For the ridiculously good apple pie she developed for Dominique’s, she would spread a layer of golden apple butter before piling in fruit and baking it. The result was an intense hit of pure apple magic at the base that would bolster the whole flavour profile and take it to the next level.

From a bit of googling this week, it seems that apple butter is very prevalent in the US but doesn’t seem to be used as much here in the UK. So, it may surprise you when I tell you that apple butter actually contains no butter. But peanut butter is in the same boat and seems to always get away with it, so I hope you don’t feel too let down.

Apple butter is made by slowly cooking down diced apples with water, sugar and cider vinegar. It begins as a pale soupy looking mess, but by the end of cooking it has reduced by half and will be a deep amber colour - it is sweet, but the vinegar provides a needed tang to cut through and make it all taste even apple-ier. Although the light brown sugar does play a role in the colour and final flavour, the main body of the butter is thanks to the slow caramelization of the sugars in the apple as the liquid is evaporated and the mix becomes ultra intense.

But apples are not created equal. This week, I sourced my apples from two places. The first was a lovely farm shop in Devon near where I’m staying - on offer? Galas (the red sort) and Spartans (little sharp fellas). The second place was Lidl, where I got a couple of bags of Granny Smiths for tests.

Although I didn’t need the apples to hold their shape this week, I’m always interested to see how the apples behave and I’m going to make it my goal this year to make a proper table of apples and how they behave when baking, as I’m often at a loss on which to use and always find myself last minute panic googling. On cooking the apples this week, I found that both the Granny Smith and Galas collapsed very quickly, whilst the spartans held their shape brilliantly and made me desperate to make apple pie. Flavour wise, they were all reasonably similar and nothing was *too* distinct or sour.

You’ve got this: Caramel

I get it. Caramel can be scary. But it doesn’t have to be. This week, we’re going to make a caramel in the simplest way possible - you can stir it, you can move it around and I promise it isn’t going to crystallise.*

You’ve probably heard about the wet caramel vs the dry caramel methods. We will cover wet caramels in the future (which I think give you a better control on colour but do require you to step away from the pan and not agitate it at all), I do want a really lovely dark caramel here so we’ll simply be adding sugar - ALL OF IT - to a clean saucepan and heating it gently until it all dissolves, stirring to encourage it to melt. By the time it is all melted, the colour will be perfectly dark and ready to add cream, apple butter and salt. 

Shall we get on with the recipe?

Apple caramel shortbreads

I use a 20cm / 8 inch square tin

Apple butter ingredients

  • 400g apples - Galas / Granny smiths worked very well as they reduce quickly

  • 200g water

  • 60g cider vinegar

  • 40g light brown sugar

  • 5g salt

Note - this will reduce down to approx 200g

Brown butter buckwheat shortbread

  • 150g solidified brown butter (you probably should brown 200g butter to get this volume)

  • 95g caster sugar

  • 160g plain flour

  • 90g buckwheat flour

  • 3g salt

For GF / 100% buckwheat shortbread

  • 150g brown butter

  • 95g caster sugar

  • 250g buckwheat flour

  • 50g milk (binding agent)

  • 3g salt

Salted apple caramel

  • 150g caster sugar

  • 75g butter

  • 85g double cream

  • 85g apple butter

  • 2g salt

Apple butter method

  • Dice the apples and put into a saucepan with all the other ingredients

  • Heat on a medium heat for 20 mins until apples are soft

  • Reduce heat and cook until the apples have reduced significantly and are a deep amber colour - around 2 hours - stirring regularly 

  • Let cool before using. Apple butter will last in the fridge happily for 7+ days

Brown butter shortbread - brown butter method

  • First, brown the butter. Heat 200g butter in a sauce pan and allow to melt. It will be noisy whilst all the water evaporates

  • Once it gets quiet, it will be foamy and the butter will be browning quite fast at this stage. Use a spoon or spatula to scrape the milk solids as they will want to stick to the bottom of the pan

  • Do your best to clear the foam and check the colour of your brown butter. I like to go for a deep amber

  • As soon as it is the right colour, take it off the heat and pour into a heatsafe container. Stir to help cool it down for a minute or so

  • Leave it to cool completely until solid - 1-2 hours in the fridge

Brown butter shortbread - shortbread method

  • Line a 20cm tin ensuring you leave some overhang so you can easily lift the shortbread out later

  • Pre-heat the oven to 160c fan

  • Paddle the brown butter and sugar until light and creamy

  • Stir through the flours and salt and paddle until it clumps together

  • If you are doing the 100% buckwheat version, add the milk bit by bit

  • Press into a tin and stab with a fork to help it bake evenly

  • Bake for 25-30 mins until golden

  • Allow to cool completely

Assembling - apple butter

  • Once the shortbread is cool, cover with 100g of apple butter. I use a palette knife to make sure it's even

Assembling - apple caramel

  • Heat a saucepan or deep frying pan. Make sure it’s clean. Sometimes caramels go wrong because there is some contamination!

  • Add all of the sugar and stir it until melted and deep amber. Use a spoon/spatula to crush any pesky lumps of sugar that don’t want to melt. You can always remove from the heat and crush the lumps if they are not going away! Turn the heat right down once it has reached the right colour

  • Add in the butter - note that it will froth and foam

  • Next, add in the double cream followed by the apple butter and salt. Whisk to combine

  • Pour over the apple buttered shortbread base

  • Allow to set completely - at least 4 hours. You can speed this up in the freezer


  • If the caramel feels a bit tacky, I like to put in the freezer for 20-30 mins until its a bit firmer to make it easier to cut neatly

  • The most important thing to make clean cuts is to WIPE YOUR KNIFE EACH TIME! You can also level up your neatness cutting by wiping the knife with a cloth soaked in hot water which heats the blade up slightly. But please make sure your knife is dry before using it

  • First, trim the edges of your shortbread. Then cut in half, turn it around and in half again so you are left with four equal squares. Now divide these into four equal squares

  • The shortbread might crumble a bit as you cut it but don’t worry. Just persevere. No one will notice!

  • Finish with a little flaky salt

  • You can keep caramel at room temp for 2 days so you don’t need to refrigerate immediately OR you can keep these in the fridge (my preference) for up to 5 days


  • Solo shortbread: These shortbread are delicious on their own. Simply make the shortbread, press it together then bake in a tin (cut whilst warm) or press the dough together on the bench to be about 1cm tall and then cut into squares to bake. If I’m baking the shortbread on its own, I like to egg wash and finish with demerara sugar. Bake on 160c fan for 12-15 mins until golden

  • Apple pie aka Nutrigrain bars: Make the apple butter and cool it down. Make the shortbread and press half of it into the tin. Spread apple butter on top. Put in the freezer for 20 mins to firm up and then cover it with the rest of the shortbread. Bake for 35-40 mins on 160c fan