Line a 20 x 20cm tin with baking parchment. Melt the chocolate, butter and syrup in a heatproof bowl over a pan of just simmering water, stirring frequently until smooth, or use the microwave, stirring between 30 second blasts.

Remove the chocolate from the heat, then stir in the vanilla, biscuit rubble, popcorn, rice crispies and raisins. Mix well until everything is well coated in the chocolate. Transfer to the tin, packing it in and smoothing over the surface. Press the mini chocolate eggs into the top in rows of five (so that there's an egg for every one of 25 bites), then scatter over the sprinkles, also lightly pressing them in. Chill for at least 2 hours before cutting into 25 squares.