- Line a 20x30cm/8x12in baking tin with baking paper.
- Place the dark and milk chocolate pieces in a large heatproof bowl and add the golden syrup and butter. Set the bowl over a pan of barely simmering water but do not allow the bottom of the bowl to touch the water. Stir from time to time until the butter and chocolate are melted and the mixture is smooth. Remove from the heat and leave to cool for 5 minutes – if this is too hot the marshmallows will melt.
- Cut the chocolate mini eggs in half (leaving a few whole) and set aside one third of the eggs, including the whole ones for decorating.
- Gently fold in the chocolate eggs, biscuits, marshmallows and raisins into the chocolate mixture and mix to combine. Spoon into the prepared tin and spread level using the back of the spoon. Scatter with the reserved whole and halved mini eggs.
- Refrigerate for at least 1 hour, or until completely firm. Cut into bars to serve.
175g/6oz dark chocolate pieces - 283900
125g/4½oz milk chocolate pieces - 283910
2 tbsp golden syrup - 264831
75g/2¾oz unsalted butter, diced - 350131
160g/5¾oz sugar-coated mini chocolate eggs - 374080
200g/7oz digestives or rich tea biscuits, broken into pieces - 303151
75g/2¾oz mini marshmallows - 283940
75g/2¾oz raisins - 142121