Collect the marshmallow Pufflers hidden under the frosting.
Make matches on top of the frosting to remove it and to uncover the Pufflers. Beware though, as the Pufflers will hear you trying to break through and they'll move after each attempt.
If you watch carefully, you can see the clues as to where they're moving to.
Make sure you catch enough Pufflers before you run out of moves, or you'll need to play the level again!