6 tbsp golden syrup
400g/14oz milk chocolate, broken into pieces
75g/3oz dark chocolate (approx. 52% cocoa solids), broken into pieces
500g/1lb 2oz digestive biscuits, roughly crushed to nut-sized pieces
4 x 32g chocolate coated honeycomb bars, cut into bite-sized pieces
225g/8oz butter, cubed, plus extra for greasing