If the recipe is a scratch recipe, you need to cook your cakes at 325..slower is better. We freeze our cakes and then ice while frozen..and we have never had a dry cake. Also we use a lot of butter, if a recipe calls for 1 1/2 stick we use 2 or especially a red velvet cake we use extra because it is a dry cake. We also brush a simple syrup on the tops of our cakes before they go into the freezer..saran wrap, then foil.
