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Ok, let's start by addressing the name of this recipe! I didn't invent the term "slutty brownies" however it has become an increasingly common way to refer to what are also know as brookies. Brookies are a type of traybake made up of a layer of cookie dough, a layer of Oreos and then brownie mix on top. As soon as I saw the new Biscoff sandwich biscuits, I knew I wanted to make Biscoff Slutty Brownies (aka Biscoff Brookies) with them! Let's go through the layers. First we have a cookie dough layer dotted with both milk and white chocolate chips. Then in the middle are Biscoff sandwich biscuits - two circular speculoos biscuits with a biscoff creme in the centre. On top are rich chocolate brownies swirled with Biscoff spread. They are incredibly indulgent and SO delicious!!

Ingredient Tips & Equipment Information

Make sure your eggs and the butter for the cookie dough are at room temperature before you start baking. The butter for the brownies can be cold for this recipe, as you are going to melt it anyway. It will just take slightly longer to melt.
I used unsalted butter for this recipe.
I used light brown soft sugar for the cookie dough and the brownies, but you can also use caster sugar.
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 Slutty Brownies

Start by making the cookie dough layer. Mix butter and light brown sugar together, then add milk and vanilla extract. Then mix in plain flour, salt and chocolate chips. Press it into the bottom of your tin.

For the brownie layer, melt butter and dark chocolate together in a pan on a low heat. In a mixing bowl, whisk together light brown sugar, vanilla extract and eggs. Then pour the chocolate mixture into the egg mixture and whisk to combine.

Then stir in plain flour, cocoa powder and chocolate chips. Before adding the brownie mix to the tin, first place the Biscoff sandwich biscuits all over the top of the cookie dough.

Then add the brownie mixture on top and then spoonfuls of Biscoff spread. Use a knife to swirl the Biscoff spread around, then put it in the oven to bake.

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. 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 is not gluten free, but it is vegan.

What if you can't find Biscoff sandwich biscuits?

You can use regular Lotus Biscoff biscuits instead for the biscuit layer. I got the sandwich biscuits from Tesco, and Sainsburys sell them too. You can also order them online from Amazon.

Why are they called Slutty Brownies?

I have to say I am not a huge fan of the name, I much prefer the terms brookies or ultimate cookie dough brownies (both better names if you're making them with your kids!) But the internet has grasped onto the term and it's now the most well known way to refer to this combination. From my research, the concept of Slutty Brownies emerged online in May 2011. Both KevinAndAmanda.com and The Londoner are credited with being the first to post recipes. Their recipes both use box mixes, which I personally cannot endorse as I am very much a make it from scratch girl! However, myself (along with thousands of others I'm sure) will always be grateful for them for introducing this recipe concept to the world!

How should the brownies be stored and can they be frozen?

They should be stored in an airtight container, or covered on a plate, in a cool place for 3 days. You can also freeze the brownies. Once they are fully cool, wrap them well and freeze for up to 3 months.

Can the brownies be made gluten or dairy free?

Yes! For gluten free you can replace the plain flour with a gluten free plain flour blend. You may like to add ¼ tsp xanthan gum to the cookie dough for better texture. For a dairy free version, use a dairy free baking spread instead of butter, dairy free milk and a dairy free dark chocolate for the brownies.

More tips for making the Biscoff Slutty Brownies:

II used a mixture of white and milk chocolate chips for the cookies, and dark chocolate chips for the brownies. You can mix this up any way you prefer. Use white chocolate chips only for example, or dark chocolate in the cookies and white and milk in the brownies - whatever you fancy!
If you can't find the Biscoff sandwich biscuits, you can sandwich two regular Biscoff biscuits together with some Biscoff spread in between them.

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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