Crumble the cake into a bowl.

In another bowl, melt the white chocolate.

Drizzle some melted chocolate into the crumbled cake and stir it in.

Squeeze some cake in your hand. If it stays as one blob then you're ready to shape into balls. Otherwise, add a little more white chocolate until the mixture holds its shape.

Using about a tablespoon of mixture at a time, shape it into tight balls and place on a baking paper lined plate.

Cover and refrigerate for 30 minutes.

Melt some more white chocolate.

Use a fork to dip the cake balls in the white chocolate, shake off any excess chocolate and place them on another plate lined with baking paper.

Refrigerate until the chocolate has set.

Pipe the pupil and blood onto the cake balls and leave them to set.