What type of leavening is primarily used in chiffon cakes?

Chiffon cakes are distinctively known for their light and airy texture, which is achieved through the use of both baking powder and the airy structure provided by egg foam. In a chiffon cake recipe, egg whites are whipped to form a stable foam. This foam incorporates air into the batter, contributing to the cake's rise and lightness.

In addition to the air incorporated by the egg whites, baking powder is added to provide additional leavening. The baking powder reacts during baking, creating carbon dioxide bubbles that further lift the cake. This combination of the leavening power from the egg foam and baking powder works synergistically, resulting in a tender and fluffy texture characteristic of chiffon cakes.

Other types of leavening methods, such as using only yeast or baking soda without the combination of whipped egg whites and baking powder, do not align with the chiffon cake's unique preparation and textural properties. Thus, the choice that highlights the use of both baking powder and air from egg foam accurately reflects the essential leavening factors in chiffon cakes.