Unfrosted cake layers are easy to store in the freezer for up to two months. Once the cakes are completely cool, wrap the individual layers in plastic wrap or store in zip-top bags. Frozen cake layers are actually easier to frost, since they are firmer and fewer crumbs escape, so no need to bring them to room temperature before proceeding. Frosted cakes can also be frozen, so long as they are coated in buttercream or cream cheese frosting and not a meringue. Set the cake in the freezer for 30 minutes to firm up the frosting, and then wrap it tightly in plastic wrap. Thaw overnight in the refrigerator or at room temperature.