This Biscoff Millionaire's Shortbread is gorgeously golden and packed with yummy Biscoff flavour! It has a buttery brown sugar and Biscoff shortbread base, topped with a perfectly golden caramel. On top you'll find white chocolate, swirls of Biscoff spread and plenty of Biscoff biscuits! If you love millionaire's shortbread, you are going to adore this Biscoff version. It has such a wonderful deep caramel flavour with a hint of spice.

Ingredient Tips & Equipment Information

Make sure your butter is at room temperature before you start baking the shortbread.
I used unsalted butter for both the shortbread and caramel layers. You can use salted butter if you like, it won't make it taste salty, instead it will balance out the sweetness. However, I do prefer to use unsalted butter and add my own salt as then I can control the salt levels. You can also use a baking spread, but butter tastes much better in my opinion. It's not that baking spread tastes bad, just that real butter is richer and creamier.
You must use plain flour (also known as all purpose flour) for the shortbread, self raising flour will make the shortbread rise, which you don't want to happen.
You must use sweetened condensed milk for the caramel layer, evaporated milk will not work.
I use granulated sugar for the caramel layer, but caster sugar (also known as superfine sugar) works well too.
Golden syrup is sold all over the world, so check the international section in your supermarket if you’re not based in the UK. You can also buy it online from Amazon (see link in the recommend equipment and ingredient section). If you can’t get hold of it, light corn syrup is the closest thing to it. You can also use light brown sugar, your caramel will look different and have slightly different texture – but it will still be delicious! Check the recipe notes for details.
You can use any kind of chocolate for the topping. I used white chocolate as it goes really well with Biscoff, but you can use milk chocolate or dark chocolate too. Pick any chocolate that is good quality and that you like the taste of, I'd advise avoiding cooking chocolate as it doesn't taste great.
Although I provide cup measurements, I highly recommend weighing your ingredients out using digital kitchen scales*. It is the most accurate way to measure ingredients and will ensure the best results. Digital scales are very low cost and can be purchased for around £12 ($16.50) .
For teaspoon (tsp) and tablespoon (tbsp) measurements, please use measuring spoons* and not the type of spoons you eat with. Again this will ensure accuracy and provide the best results.

For the full recipe with measurements, head to the recipe card at the end of this post.

How to make Biscoff Millionaire's Shortbread

Mix the butter, light brown soft sugar and Biscoff spread together until creamy. Add the vanilla and mix it in, then add the plain flour and mix until the flour is all combined.

Press the shortbread dough into the base of a lined tin and smooth it down until compact. Bake for 20-25 minutes. Leave to cool.

Make the caramel by melting butter, granulated sugar, golden syrup and condensed milk over a low heat until the butter is fully melted and the sugar has dissolved. Turn the heat up to medium and bring it to a gentle boil. While stirring constantly, let it bubble for 5-7 minutes until it is darker in colour and has thickened. Take it off the heat and mix in the vanilla, then pour it over the shortbread base. Put it in the fridge to set for 2-3 hours or leave on the kitchen counter overnight. Melt the white chocolate pour it over the top of the caramel. Smooth it out, then drizzle over warmed Biscoff spread and swirl it around with a cocktail stick. Decorate with Biscoff biscuits, leave to set then cut into slices.

For the full recipe with measurements, head to the recipe card at the end of this post.

What is Biscoff?

Biscoff spread, made by the brand Lotus, is also known as cookie butter and speculoos. It has a deep caramel flavour and a hint of cinnamon and other spices. Lotus are best known for their biscuits, which are commonly served with coffee. The biscuits are used to make the spread, and you can buy it in crunchy and smooth varieties. The spread is similar to Nutella or peanut butter in terms of texture, but it has a unique flavour. It’s also naturally vegan.

What size tin do you need for this recipe?

This recipe is for an 8" or 20cm square tin, it need to have deep sides, at least 2". If you want to use a 9" or 23cm square tin, I would recommend increasing the ingredient amounts by 25%.

What is the best way to line the tin?

I find that greasing the tin very lightly, only just enough to help the baking paper stick to it, then lining with non stick baking paper is the best way to ensure you can remove this bake easily from the tin. You should also leave an overhang of baking paper, about 1" taller than the tin. This is so you can grasp it to pull the shortbread out of the tin.

Do you need an electric mixer to make this recipe?

While it is easier to make the shortbread base in an electric stand mixer with the paddle attachment, you can absolutely make it by hand with a wooden spoon and some elbow grease! For the caramel layer and chocolate layer, no electric mixer is required.

How should it be stored and how long does it last for?

It can be stored at room temperature in an airtight container for 2 weeks (although it never lasts that long in my experience! It gets eaten up too fast!) If the caramel hasn't been boiled for long enough and is too soft, then you may need to store it in the fridge to firm it up.

Can you freeze Millionaire's Shortbread?

Yes! Wrap it well in cling film, or place in a freezer bag or tupperware container. It can be frozen for up to 3 months. It is bet freeze it sliced, then you can easily defrost a piece or two at a time. Place small squares of baking paper between each square to stop them from sticking together. Defrost at room temperature, I usually leave it on the kitchen counter for an hour or so.

How do you slice Millionaire's Shortbread neatly?

This can be one of the most daunting parts of this bake! But I am here to help! The best way I've found to slice it is to firstly make sure that the chocolate has fully set and that it is at room temperature. If the millionaire's shortbread is cold, the chocolate is very likely to crack as you slice it. Secondly, use a very sharp knife that is longer than the shortbread. This means you can slice through it in one motion. If you like you can gently score the chocolate on top to work out the sizes of the squares first. Then, with an even pressure, gently rocking and sawing the knife, push the knife slowly through the chocolate, caramel and shortbread. It's as simple as that! Don't worry if they are not perfectly neat if it's the first time making this recipe, as with everything, practice makes perfect. Sounds like a good reason to make a few more batches right?!

Can you use a ready made caramel instead?

No, unfortunately if you want this recipe to work you do need to make the caramel from scratch. A shop bought caramel will not be thick enough and won't set like the homemade version. But don't worry, read through this post in full before you start baking and you will have the best chance of success! You can also check out my Millionaire's Shortbread guide for even more information.

Can this recipe be made gluten free?

Unfortunately Biscoff spread is not gluten free, so you cannot make the millionaire's shortbread gluten free using Biscoff spread.

Can this recipe be made dairy free?

To make this recipe dairy free, replace the butter in the shortbread and caramel with a dairy free version. I recommend a dairy free butter block, like Flora Plant or Stork Baking Block. You will also need to use a dairy free condensed milk, Carnation and Nature's Charm are brands I know of. And a dairy free chocolate for the topping. Or you can try my Vegan Millionaire's Shortbread recipe and add some Biscoff to it.

Troubleshooting

If you have any questions about this recipe, or if something went wrong and you need help, please use the comment form below and I will get back to you. You can also get in touch with me on my Twitter, Instagram or Facebook. I'd love to hear from you!

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