Separation-Foaming Method

This method is used for both cold-method genoise-type sponge cakes and baking-powder cake bases. The eggs are separated and the yolks are first whipped with a small amount of the sugar. The egg whites are whipped separately. Because the fat (the egg yolks) has been removed, it is possible to whip the egg whites to stiff peaks, which produces a cake with a lighter texture and a greater volume. If the baked cake is going to be used to create a roulade or any type of rolled cake, the butter should be left out of the recipe, as it will cause the cake to become firmer when refrigerated, resulting in cracks when the sheet is rolled.