The cake layers can be made up to three weeks in advance. If making three days in advance or less, just wrap each individual layer tightly in plastic wrap and tuck into a large sealed plastic sip-top bag. Store the cakes on the counter at room temperature. To store the layers longer than 3 three days (up to three weeks), wrap a layer of aluminum foil around the layer of saran wrap and freeze. Allow to thaw to room temperature before continuing with the recipe.