Sheet cakes are a great way to provide enough cake for a large crowd. Unfortunately, it is usually missing the extra layer of frosting of a traditional round layer cake. Stacking two sheet cakes on top of each other is an easy way to add extra frosting, dimension and quantity to the cake. A stacked layer cake can feed nearly 150 people, and creates a perfect centerpiece.
Place sheet cakes in the refrigerator to cool for at least two hours. Cakes are easier to handle when cold.
Place one layer of cake on a prepared serving plate or cardboard cake board.
Make sure the cake is flat on top. If it is not, use a serrated knife to level it out. Uneven cakes will cause an unsteady foundation and can cause top layer to slip.
Frost a thin layer all around cake if you've cut it to form a layer that will keep crumbs off the final frosting. Then frost a regular layer on top. You can use ganache - a thick chocolate frosting that provides the most stability.
Cut chopsticks or straws into lengths about a 1/2 inch longer than the cake layer. Insert them about a 1/2 inch from the edge around the cake, so that the top layer will rest on them.
Gently place the second layer on top , making sure that the edges are aligned. Frost a thin layer of frosting all around, and finish the cake according to preference.