Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans.

In a large bowl, whisk together the cake flour, baking powder, and granulated sugar.

Whip the egg whites in a clean bowl until stiff peaks form, about 3-5 minutes.

In another bowl, mix the whole milk, melted butter, and vanilla extract until smooth, then combine with dry ingredients.

Gently fold in the whipped egg whites into the batter until no streaks remain.

Pour the batter into prepared pans and bake for 25-30 minutes until golden brown.

Cool the cakes in the pans for 10 minutes, then transfer to a wire rack to cool completely.