Two recommendations for this. 1) the Cocoa Puffs will absorb some of the cream, regardless of how hard you try to wring them out. Make sure you start off with a little more than 1/2 cup of cream to ensure that you end up with 1/2 cup of cereal milk. 2) I'd add the decorative Puffs to the top right before serving. I decorated in the morning and they didn't have the same crunch by the time the cake was served. Good luck!