The Best Way To Turn a Layer Cake Into a Sheet Cake
Best part? There's no math involved!
While we'll always love the sight of a tall frosted layer cake sitting on a cake stand, layer cakes come with some challenges. They require more than one round cake pan, for starters. Then there is the question of baking and frosting the layers (don't forget the crumb coat!), and transporting the cake, if necessary. A layer cake isn't the easiest thing to bring to a party, unlike a practical (and practically foolproof) sheet cake.
If you have a favorite layer cake but would like to turn it into something more portable, it's easy to convert the recipe into a sheet cake.
Here's what you need to know:
One two-layer cake = One sheet cake
The batter for a two-layer cake made in two 9-inch round cake pans should fill one 13 by 9-inch sheet cake. You may need to increase the baking time by a few minutes, depending on the recipe. Check the center of the cake for doneness with a cake tester or wooden pick before pulling it out of the oven. The frosting amount for a two-layer cake should be enough to cover the top and sides of a sheet cake.
One three-layer cake = One two-layer sheet cake
The same principle applies to a three-layer cake recipe. If the cake is made in three 9-inch pans, it will fill two 13 by 9-inch sheet pans. You will probably have to make an extra batch of frosting, especially if you are frosting in between the two layers of the sheet cake.