- STEP 1
Line a square 20cm baking tin with parchment paper.
- STEP 2
In a large heatproof bowl, melt the chocolate, biscoff spread and butter over a pan of simmering water.
- STEP 3
Chop the biscuits into small pieces and add this to the mixture, along with the marshmallows and popcorn.
- STEP 4
Mix all the ingredients and pour into the tin. Then top with the chopped biscuits and leave to chill in the fridge overnight.
- STEP 5
Slice into squares and serve!