Preheat Oven and Prepare Pan: Preheat your oven to 350°F (175°C). Grease and flour a 9-inch round cake pan.

Sift Dry Ingredients: In a medium bowl, sift together the flour, cocoa powder, baking powder, and salt. Sifting is important for this recipe as it helps ensure a light, airy texture.

Whip Eggs and Sugar: In a large bowl, using an electric mixer, beat the eggs and granulated sugar together on high speed for 5-7 minutes. The mixture should become thick, pale, and fluffy, and it should triple in volume. Beat in the vanilla extract.

Fold in Dry Ingredients: Gently fold the sifted dry ingredients into the egg mixture using a spatula. Be careful not to overmix, as this will deflate the batter and result in a dense cake. Fold just until no streaks of flour remain.

Bake: Pour the batter into the prepared pan and spread it evenly. Bake for 25-30 minutes, or until the cake springs back when lightly touched and a toothpick inserted into the center comes out clean.

Cool and Serve: Let the cake cool in the pan for 10 minutes before inverting it onto a wire rack to cool completely. Once cool, you can dust it with powdered sugar or frost it as you like.