This bake was very much inspired by Fatties Bakery's book Salted Caramel Dreams. Flipping through the pages I was drawn to the glory that is caramel, along with how fun all of the recipes are! As fun as millionaire's shortbread seems, I haven't made it a lot over the years as I don't actually think it's that great (bear with me). I think it's very much a very simple style over substance. I wanted to make something where each layer is strong on its own yet at the same time makes the perfect bite. I was given a jar of peanut butter and so was keen to include it any my next baking project which just so happened to be this. I've ended up including it in every layer.
I would like to say my peanut butter shortbread is the best you will ever have. So much that I've written the standalone recipe for it, should you get the craving to keep making it. Salted caramel is something which I think has been overdone over the past few years, mostly because it has been done badly. At times it's either too sweet or too salty. I think the balance needs to be right, like in Salted Caramel Dreams. Peanut butter really lends itself to the sweet and saltiness of caramel and so is a great pairing for it. And just wait until you try it! One of the other problems I have with millionaire's shortbread is texture. I think the caramel layer needs some bite given it's sandwiched between set chocolate and hard shortbread. I thought it would be a bit too much to chuck peanuts into the caramel (there is such a thing as too much, right) and wondered what I could use instead. It was when I was contemplating a lunchtime snack that sweet and salted popcorn dawned on me. Again it's very popular right now and quite rightly as it's a snack which can hit a few craving spots at the same time. Given it has already been seasoned, you literally need to crush it up, mix it into the caramel, and you're done! Finally there is the chocolate top. The chocolate needs to draw people in given it's the first thing you see. It masks the caramel and shortbread and so I think it also needs to give people a hint as to what it's all about. It also needs to be fun. Millionaire's shortbread should be enjoyable to make. Looking back to the peanut butter again I decided to keep it simple. Rather than completely mix it into the chocolate, swirl them together.
Now you may ask, why have you changed the name? I wanted it to 'pop' like the corn that is in it. I'm not going to lie, it's an indulgent bake which you won't necessarily want to eat a lot of (although it's difficult to resist). To me it's something that you would treat yourself to. As a child I would have pocket money which I would use to buy sweets and treats, and this bake would be something I'd have spent that money on.
Hands-on Time 40 minutes plus chilling
Baking Time 30 minutes
Cooking Time 15 minutes
290g Unsalted butter plus extra for greasing (softened)
250g Peanut butter, smooth
1 1/2 tsp Fine salt
335g Caster sugar
300g Plain flour
30g Sweet & Salty popcorn
200ml Double cream
200g Dark chocolate (minimum 70%)
25cm x 20cm Deep-sided tin (Brownie tin)
Small microwaveable bowl
Cut a piece of baking parchment that can line the bottom and sides of the tin. I find it’s best to turn the tin upside down and shape the paper around the base, so it then fits the tin nicely when you go to line it.
Grease the insides of the tin with some butter and line with the parchment.
Add 90g of peanut butter and 190g of butter to a mixing bowl and beat with a wooden spoon until light and smooth.
Add 1/4 teaspoon of salt and 110g of sugar and beat again.
Add the flour.
This time instead of beating the mixture, fold it into the buttercream. The aim here is to combine the flour but not overwork the dough. Scrape the dough around the sides of the bowl to clean them, and make sure you don’t leave any bits at the bottom either.
Transfer into the lined tin. I find it’s best to break up the dough if it’s lumped together so you can distribute it evenly without touching it too much.
Press the dough into the edges of the tin and flatten so it’s nice and even. Try not to handle the dough too much.
Pop the tin into the fridge to chill for at least 30 minutes.
In the meantime preheat your oven to 170°C/150°C(Fan)/325°F/Gas mark 3.
Prick the top of the shortbread all over with a fork.
Pop the tin into the oven onto a middle shelf for 30 minutes until golden.
Remove from the oven and leave to sit in the tin at room temperature until cooled. At this point the shortbread should have hardened.
Using your hands, crush the popcorn so you break it up into smaller pieces.
Add 225g of sugar to a saucepan and place over a medium heat and stir occasionally with a spatula. You should slowly notice it will resemble wet sand before it starts to melt and turn golden. Stir to ensure all of the sugar has melted. If it turns too golden (i.e. dark brown) remove from the heat immediately although you may be too late.
Add the double cream and keep stirring over the heat. It will froth up and bubble. Once you have a smooth caramel, add 75g of butter, 110g of peanut butter, and 1 1/4 teaspoon of salt. Keep stirring until you have once again a smooth caramel.
Remove from the heat and add the popcorn to the pan. Stir until the popcorn is coated in the peanut buttery caramel.
Tip this onto the shortbread, spread out and flatten using the back of the spatula.
Leave to cool before popping it into the fridge for at least 30 minutes.
When you’re ready to add the chocolate swirly top, add 50g of peanut butter to a small microwaveable bowl and pop into the microwave for no longer than 30 seconds until it’s smooth and runny.
Break the chocolate up into a microwaveable bowl and pop into the microwave for 30 second blasts. In-between rests give the chocolate a stir using a clean spatula.
Once the chocolate has melted, add 25g of butter and stir until incorporated.
Tip this over the caramel layer and spread out using the back of the spatula.
Using a teaspoon, randomly dollop the peanut butter on top of the melted chocolate.
Using the handle of the spoon, drag it through the peanut butter spots so you create swirls. There is no right way to do this! Have fun!
Leave to cool and set before returning to the fridge.
When you’re ready to portion it up remove the tray from the fridge. Lift the shortbread carefully out of the tin using the parchment. I would recommend you lift using the longest sides of the parchment, otherwise there’s a chance your shortbread may break in half from the weight if you lift using the narrower ends.
Allow to sit at room temperature for 10 minutes.
Use a long sharp knife to cut it up.