Use a fork to prick holes at 1" intervals into cake. Pour syrup (see below) over cake allowing syrup to soak into the holes. Use cutter to cut circles out of cake and set on a piece of parchment paper. Fill a pastry bag fitted with large round tip with buttercream icing. Take push-pop cylinder and sprinkle a small amount of crunch, chips, or powder in bottom of cylinder. Push a cut circle down on top of the peppermint then pipe a layer of buttercream on top. Sprinkle with peppermint then repeat the process until the cylinder is full. Finish with a swirl of buttercream and a sprinkle of peppermint.
1/3 cup butter
1 cup sugar
1/3 cup milk
1/2 tsp. or 15 drops of peppermint flavoring or oil
Melt butter. Stir in remaining ingredients. Bring to a boil and boil 3 minutes, stirring constantly. Pour over cake while still hot.