Step 1Line a large baking tray with baking paper or plastic wrap.
Step 2Place cake in a food processor bowl and pulse until it makes rough crumbs. Or crumble cake with your fingers and hash with a fork.
Step 3Roll mixture into 20 small balls.
Step 4Place dark chocolate in a small, shallow microwave-safe bowl and microwave on low for 1 minute. Remove jug from microwave and stir chocolate with a dry fork. Repeat in 1-minute intervals until chocolate is melted.
Step 5Use a fork to dip one of the mini-pudding balls into melted chocolate and turn to coat. Place truffle on prepared baking tray. Repeat process with remaining balls. Place tray in fridge for 10 minutes or until truffles set.
Step 6Place white chocolate in a small dry microwave-safe bowl and microwave on low for 1 minute. Remove jug from microwave and stir chocolate with a dry fork. Repeat in one-minute intervals until chocolate is melted.
Step 7Spoon melted white chocolate onto the top of truffles. Press a piece of cherry lightly into chocolate.
Step 8Set truffles aside or return to fridge until set then serve.