How to Frost A Cake
If the cake is very soft and crumbly, apply a “crumb coating” to prevent cake crumbs from mixing with the frosting. Spread a thin layer of frosting over the entire cake, then let stand 5 to 10 min. or until frosting is set. Spread remaining frosting over cake.
Make sure cakes are completely cooled before frosting. A warm cake can cause the frosting to soften or melt.