While both angel food cake and sponge cake rely on beaten eggs to make them light as a feather, they are far from being the same thing. Yes, they are similar, both have a springy texture that delights any palate, but the biggest difference between a sponge cake and angel food cake is which part of the egg they use. On the one hand, angel food cake only requires egg whites to keep it as light as possible — they simply need to be whipped into soft peaks to create a fluffy, airy batter. On the other hand, sponge cake uses both egg whites and egg yolks, previously beaten separately and then combined together with the other ingredients. This gives an extra point of flavor to sponge cake and a slightly denser texture. In addition, some angel food cake recipes specify that cake flour must be used since it doesn't weigh down the egg whites, while sponge cake can use all-purpose flour without any problem. And if we talk about pans in which these cakes can be baked, there is another clear difference — angel food cakes are mainly baked in tube pans, but sponge cakes can be baked in virtually any cake pan.