Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans with butter or non-stick spray.

In a medium bowl, whisk together the cake flour, baking powder, and granulated sugar until well combined.

In a clean mixing bowl, use an electric mixer to whip the egg whites until they reach stiff peaks (3-5 minutes on high speed).

In another bowl, combine the whole milk, melted butter, and pure vanilla extract. Whisk until smooth.

Gradually incorporate the wet ingredients into the dry mixture, stirring gently until just combined.

Gently fold the whipped egg whites into the batter using a spatula until well combined.

Divide the batter evenly between the prepared cake pans and smooth the tops with a spatula. Bake for 25-30 minutes.

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