Break the Christmas cake into pieces then blend in the food processor for a few minutes to turn into crumbs.
Divide the mix into 12 and shape into balls. Place in the fridge for a couple of hours to firm up.
Melt the chocolates in separate bowls, over pans of simmering water or in a microwave.
Make a hole in each ball with a lolly stick, then dip the end of the stick in the melted chocolate and place back in the hole. Repeat with the other sticks and leave to set for about 30 minutes.
Re-melt the chocolate if necessary, then, using a teaspoon pour the chocolate over a cake pop, holding it over the bowl. Work quickly to get a smooth finish. Tap the cake pop on the side of the bowl to get rid of the excess chocolate, then stick into a piece of polystyrene or upturned colander while you coat the rest of the pops.
Once the chocolate has set slightly, but is still sticky, coat in sprinkles then leave to set completely.