Mix together the cake crumbs, icing sugar and cocoa powder.
Add the flavouring and milk. Mix until the ingredients are well combined and stick together.
Using your hands mush together the mixture until it is almost evenly coloured. Wash your hands. The next step is easier with clean hands.
Pinch off a small sprout sized piece of truffle mixture. Roll into a ball and set to one side.
Drizzle a small amount of the glace icing on to the top of the pudding, then decorate with the fondant holly. Chill for an hour to allow to set.