When you are making a layer cake, one of the most important steps in decorating it is applying a crumb coat. The crumb coat is a very thin layer of icing that you cover the entire cake with, and the purpose is to contain any crumbs that might have come loose as a result of leveling the cake layers or might otherwise be sitting on the surface of the cake. After the crumb coat is applied, the cake is usually refrigerated to allow it to set before covering it up with the “real” frosting – which should be completely crumb-free.
Many home bakers skip the crumb coat step of cake-making because of time constraints and because it often requires you to make a larger batch of frosting so that you don’t have to stretch a recipe too far. One alternative is a relatively new product from Wilton called Spray-N-Seal Crumb Sealing Spray. This is a coconut oil spray that can be applied to an unfrosted cake to lock in crumbs and give you a perfect decorating surface. The coconut oil is a liquid within the can of spray, and once it is applied, the cake is chilled for 2-3 minutes to set the oil. The thin layer of oil (which is comprable to the layer of cooking spray you might put on a cake pan to grease it) solidifies in the fridge and is easy to frost. As the cake comes back to room temperature, the thin layer of coconut oil absorbs back into the cake without adding any greasiness or potentially unwanted flavor to your cake.