Blitz the biscuits in a food processor to a small crumb, and add the melted butter – either pulse in the food processor a few times until the mixture is combined, or mix it in a bowl.
Tip the biscuits into a lined 9x9" square tin and press down firmly.
For the Homemade Caramel
In a large saucepan pour the condensed milk, butter, sugar, and golden syrup and melt on a medium heat till the sugar has dissolved – stir frequently to stop anything from catching.
Once the sugar has dissolved, turn the heat up high and let the mixture come to boiling point and boil for 5-7 minutes stiring constantly so that the mixture doesn’t catch. BE CAREFUL as the mixture is VERY hot and can burn you if it splashes back!
The mixture will be ready when it has changed to a slightly darker golden colour, and has thickened to a soft fudge texture!
Pour the caramel onto the biscuit base and leave to set for one-two hours on the side. If it's hot, set in the fridge!
For the Chocolate Biscoff Layer
Melt your milk chocolate down carefully in the microwave, or in a bain-marie.
Also, in a separate bowl, melt the Biscoff spread for about 30-40 seconds so that it's softer and not as hard.
Mix the two together, and spread on top of the caramel. Sprinkle over some Biscoff crumbs and then set on the side or in the fridge.
Once set, cut up your pieces and enjoy!
Notes
This will keep in an airtight container for at least 1 week – if they last that long!
If you caramel is rock solid when you remove it from the fridge, you have slightly over done it. Not to worry though, when you pour the chocolate on, leave it to set at room temperature rather than in the fridge and it should soften the caramel slightly.
Biscoff spread is found in most supermarkets - you can use smooth or crunchy!
If you don't want to use the spread, you can use 300g of chocolate on the top, and plenty more biscuits!
Using a tinned caramel in place of making your own, will NOT work. Tinned caramels do not set, so it'll be messy.
You can use fewer biscuits if you don't want it as thick. Use 400g, with 135g of butter.