Boxed cake mixes are known for being easy alternatives to homemade cakes. They taste good, and tend to be moister than many homemade versions. But a moist cake poses a challenge when it comes time to frost. The key to frosting a box cake is to make it firmer by freezing it.
Freezing a Box Cake
Freezing is the secret to making a cake made from a boxed mix firmer for frosting. The freezing process helps slightly condense the cake and prevent crumbs. Wrap the completely cooled cake several times in plastic wrap. The cake has to be cooled or you’ll end up with a soggy dessert. Freeze the cake for several hours. Let the cake warm up to just below room temperature before frosting. Frosting a frozen cake traps the moisture that's released during the thawing process, which also leads to soggy cake. Frost the mostly warmed cake and allow the cake to continue warming up until you're ready to serve it.