150g butter, cubed, plus extra for the tin
3 tbsp caster sugar
3 tbsp golden syrup
6 tsp cocoa powder
225g biscuits, crushed
Handful of raisins
110g milk chocolate
110g dark chocolate
STEP 1 - Butter and line a 15-20cm tin with baking parchment. In a large saucepan, melt the butter, sugar, syrup and cocoa. Stir through the biscuits and raisins.
STEP 2 - Pour the mixture into the prepared tin and press down, then smooth the top with the back of a spoon. Microwave both chocolates in short 20 second bursts, stirring frequently, until melted. Pour them over the mixture in the tin. Use a palette knife or spoon to smooth over, so it's completely coated in chocolate.
STEP 3 - Put the tin into the fridge and leave for about 2 hrs to set, or overnight. Run a kitchen knife under the hot tap then cut into squares.