Covering a cake with fondant can seem intimidating if you’ve never tried it. It’s the same way that frosting a layer cake can seem intimidating if you’ve only ever spread frosting on top of a sheet cake that is still in the pan it was baked in. But just like getting past that first layer cake, covering a cake with fondant isn’t as difficult a task as it may seem, and it is a very useful skill to have if you want to engage in a little recreational cake decorating!
Before we get started, there are a few things to know. First, you can read all about what fondant is here. Fondant comes unflavored and doesn’t taste great on its own. You can add flavor to it by kneading in flavored extracts. Simply add a teaspoon or so of vanilla (or other flavors) and knead it until well incorporated, then continue as I describe below. You can add color by kneading in food coloring in the same way. You can buy it both colored and flavored. Here, I’m using a plain white fondant without flavoring.
Start with a cake that has been thoroughly cooled. Spread it with a thin layer of frosting, as though you’re making a crumb coat, and let it set before working with it. Don’t make the frosting too thick or the fondant may slide once it is applied. You can chill the cake for a few minutes to make it easier to handle if the icing is soft. When you’re ready to begin, assuming that you’re starting with packaged fondant, the first thing you do is lightly dust a smooth, clean work surface with cornstarch or confectioners sugar (I prefer confectioners’ sugar). Start kneading the fondant on the work surface until it is pliable.
Once it is pliable and easy to knead, roll it out into a big circle that is approximately 1/8th of an inch thick. Keep turning the fondant and add more cornstarch/sugar to the surface as needed to ensure that it does not stick. Feel free to try to go thinner if you are able to, but you still need to be able to move the fondant without it tearing, so thinner is not always better. The circle should be big enough to cover your cake, both top and sides. Estimate this size, then add about 2 extra inches all around.
Gently transfer the fondant to the cake, centering the piece of fondant in the middle of the cake. Rolling the fondant and then unrolling it is a popular method, as is draping the fondant carefully. Folding the fondant, as you might do for a pie crust, will create unsightly lines on the surface. Start at the center of the top of the cake and begin to push the fondant down and out towards the edge of the cake. This pushes out all the air bubbles and creates a smooth surface.
Push the fondant down the sides of the cake, smoothing and stretching as you go, until you reach the cake plate. Press the fondant firmly to “seal” it. When the cake is finished, take a sharp knife and cut off excess fondant around the edge of the cake. Do not reuse fondant that has had icing stuck to it, as it becomes very sticky and hard to work with. Now you can decorate you cake in any way you want to, whether you’re going to pipe on fancy icing decorations or paint a beautiful backdrop with edible food colorings!