Raising Cake

• Three baking techniques create and sustain the tiny bubbles that let cake batter expand and rise in the heat of baking. A leavening agent, like yeast, baking soda or baking powder, is particularly useful with moist, dense doughs like fruitcake. Creaming fat and sugar together creates tiny pockets of air that raise many varieties of layer cake. Foam cakes depend on the air bubbles created when sugar is beaten with egg whites or whole eggs for several minutes. This process produces unshortened cakes such as angel food, sponge and meringue cakes.

Angel Food Cake

• Angel food cake is the simplest of unshortened foam cakes, using only the whites of eggs to raise the cake. Superfine or powdered sugar is added as egg whites are beaten into stiff peaks, and then more sugar and flour are gently folded into the egg whites to form the final fat-free batter. Classic angel food cake is flavored with vanilla, although other flavorings can be used.

Sponge Cake

• To make a sponge cake, separate egg yolks from whites. This unshortened cake requires both, but first egg yolks are combined with sugar and flavorings into a smooth batter. Then you fold stiffly beaten egg whites gently into the batter, making it light and filling it with air. A simple sponge cake contains only eggs, sugar, flour and flavorings.

Meringue Cakes

• While some people might argue that a cake-sized Pavlova meringue is not really a cake, foam cakes include several classics founded on meringue. The first step is to beat fine sugar into egg white. This meringue is then enriched with flour and more sugar. A Pavlova meringue contains only a few spoonfuls of cornstarch, called corn flour in Britain, and a Dacquoise substitutes finely ground nuts for this bit of starch.