Step 1

Process the madeira cake in a food processor until coarse crumbs form. Melt the chocolate in a heatproof bowl over a saucepan of simmering water (make sure the bowl doesn’t touch the water). Stir until smooth. Add the cake crumbs and stir to combine.

Step 2

Roll level tablespoons of mixture into balls, squeezing firmly as you roll. Place the hundreds and thousands on a plate.

Step 3

Combine the icing sugar and boiling water in a small bowl. Use 2 forks to carefully dip a truffle into the icing to coat. Tap forks on side of bowl to remove excess (you only need a very thin coating). Carefully roll in hundreds and thousands to coat. Transfer to a tray. Repeat with remaining truffles, icing and hundreds and thousands. Set aside to set. Place in an airtight container and store in the fridge for up to 3 days.