Do you know what the following cakes have in common? Génoise, chiffon, the French biscuit, your bubi’s Passover Sponge, the so-called "hot milk sponge," many nut tortes, and ladyfingers, too?
All of these cakes belong in the sponge or “foam” cake family because they get their structure and spongy, light, and open texture from whipped whole eggs or whipped egg whites a.k.a. egg foams. Sponge cakes contain plenty of eggs, but little or no butter (although chiffon cakes do contain a generous amount of oil). All of these cakes require hand folding: Dry ingredients (and sometimes butter) are folded into whipped whole eggs, or else whipped egg whites are folded into the rest of the batter.
Sponge cake is not defined by the type of flour or particulate: My book Flavor Flours is filled with all kinds of sponge cakes made from other flours. The fact that structure comes from eggs rather than gluten is actually a great help in gluten-free baking because it allows us to make endless nice cakes without adding gums or additional ingredients for structure.
American sponge cakes—chiffon cakes, feather or daffodil sponges—and nut sponge cakes, are rich and moist and flavorful enough to be the main event. They are glorious plain or with a little fruit and whipped cream.
European sponges like génoise and the French biscuit (nothing to do with American biscuits or English cookies) and ladyfingers are purposely plain and relatively dry. These are used as components in elaborate multi-layered desserts where they sponge (!) up delicious juices, liqueurs, or syrups and are used in-between layers (or as containers for) for rich buttercream, ganache, or mousse fillings.
Sponge cakes are relatively simple and quick to make, but for success, you must be a skillful folder.
Génoise is the trickiest: Well-sifted flour and hot melted butter must be folded into a delicate whole egg foam by hand, without deflating the foam more than necessary. Other sponge cakes require folding properly-whipped egg whites into the thicker and heavier portion of the batter. To make it all even more fun, the European sponges rarely call for baking powder or baking soda—so the only leavening comes from the air bubbles in the foam and the baker’s ability to fold without breaking to many of those bubbles.
Sponges that require folding whipped egg whites into the remaining batter are usually a bit easier, especially if the recipe also calls for baking powder. If you have never made a sponge cake before, take advantage of the extra egg whites and generous baking powder in a chiffon cake.
Here’s a breakdown, from richest and moistest to lightest and—usually but not always—driest.
Some categories may be a bit blurry, and there may be plenty of hybrids out there—since bakers and pastry chefs are born to tinker.
Have you mastered sponge cakes? Share your tips in the comments below!