- STEP 1
Lightly grease a 15cm (6in) shallow square tin.
- STEP 2
Cut the Mars bars into thin slices and put in pan with 75g of butter. Leave on low heat until melted, then beat till smooth.
- STEP 3
Stir in the rice crispies. Chill for an hour, (till set).
- STEP 4
Next put the chocolate and butter in a bowl and melt over hot water on a low heat and spread ontop.