1. Melt the chocolate in a glass bowl over a pan of simmering water, or in a microwave if you have one. Take care not to overheat it or it will burn.
2. Break the cake into crumbs with your fingers then stir it into the chocolate. Leave the mixture for a few minutes to cool.
3. Shape the mixture into eight small balls. Roll them in the chocolate vermicelli or sugar strands or dip them into more melted chocolate. Leave them on a wire rack for 20 minutes to set.
4. Place the truffles into the paper cases.
Yummy!