One of the most fundamental skills required for artisan cake shaping is learning the art of knife carving a layer cake. Forming a pyramid cake from several stacked pieces of sheet cake is a design that's dramatic while still being a relatively easy first shape to master. This cake makes a great centerpiece for an Egyptian or geometry-themed party or any occasion where you want a pastry with a more interesting shape.
Bake and cut sheet cake squares in graduated sizes. Bake large sheet cakes, then cut into square pieces; one 10 inches by 10 inches, one 8 by 8, one 6 by 6, one 4 by 4, one 2 by 2 and one 1 by 1, for the top.
Stack pieces of sheet cake to form a multi-tiered stack. Place the largest square on the bottom with each successively smaller square placed in order after that. Apply a layer of frosting between each layer to make them stick.
Shave down the sides of the cake. Starting at the top tier, use the bread knife to cut away the protruding corners of each square layer, transforming each of the four sides into a flat plane sloping down from the top. Rotate the cake around often as you work, shaving away the largest of the excess bulk on each side before refining the shape of each side.
Frost the cake. Apply frosting to the cake in generous amounts, smoothing with downward motions from the top to the base. Use more frosting than you need and remove extra, rather than trying to spread too little over a large area; this will help prevent tearing the cake.