Baking

• Sheet cakes are generally thinner than round layer cakes, so you must be careful not to overcook them. The amount of time need to bake will depend on the thickness of your pan and the cake batter. The best test is to poke a toothpick in the center of the cake. If it comes out clean, it is ready. If it is still wet, let it bake another five minutes and check it again.
  
  There is a fear of any cake breaking or sticking to the pan when removing it. Sheet cakes are especially prone to this mishap, because of their size. The best way to ensure that your sheet cake will come out of the pan easily, after baking, is to prepare the pan by spraying the sides with cooking oil spray. Then place a sheet of parchment paper or waxed paper on the bottom of the pan, before pouring in the batter. Use a thin spatula to ease any sides of the cake that may have stuck when it's done baking. Then turn the sheet cake over, quickly, onto a cake base (foil covered cardboard works well).
  
  

Filling and Double Layers

• If you would like to make a double-layer sheet cake with filling, it can be done in several ways. You can torte a single sheet cake, which can be difficult. Torte means to cut the single layer in half, through the middle, horizontally. You will need to remove the top layer with a flat cookie sheet, while you spread the filling on the bottom layer. The second way to create a two layer sheet cake is to cut the cake in half, fold one half on top of the other after you spread the filling on. This will give you a half sheet cake. The other option is to simply, bake two sheet cakes. Spread the filling on one and place the other cake on top. An extra pair of hands is very helpful, no matter which process you choose for making a filled, double-layer sheet cake.
  
  

More Tips

• The cake will be easier to handle if you cover it with plastic wrap and place it in the refrigerator for a couple of hours or even overnight. It can even be frozen if you will not be preparing it for several days.
  
  Start the frosting of the cake on the sides. Spread the frosting smoothly with a thin, flat spatula and then round out the corners. Put a heaping amount of frosting on the top of the cake and then work the spatula over the top, until the cake top is covered. Smooth the frosting by making a back and forth motion with the spatula, from one end to the other.