Have to use baking powder make a sponge cake?

* Sponge cakes rely on air for their lightness. Baking powder provides the chemical reaction that creates air bubbles in the batter, resulting in a light and airy texture.

* Without baking powder, the cake will be dense and flat. While you can achieve a certain amount of airiness through vigorous whisking of the eggs, it's not enough to create a true sponge cake texture.

* Baking powder is a reliable leavening agent. It's readily available, affordable, and consistent in its results.

However, there are some recipes that use alternative methods for leavening:

* Angel food cakes rely solely on whipped egg whites for their lightness.

* Some sponge cakes may use baking soda and an acidic ingredient like lemon juice to create a chemical reaction for leavening.

Ultimately, the decision to use baking powder in a sponge cake depends on the recipe and your desired outcome. If you want a traditional, light and airy sponge cake, using baking powder is the best way to go.