Preheat the oven to 400 degrees Fahrenheit. Set aside an 8-inch circular pan with parchment paper on the bottom and edges.
In a mixing bowl, whip the egg whites for 2 to 3 minutes on low speed, or until soft peaks form.
While continuing to beat, gradually add 1/4 cup granulated sugar, a tablespoon at a time. After all of the sugar has been added, increase the speed to medium and continue beating the meringue until stiff, glossy peaks form. Remove from the equation.
Cream the butter and remaining 1/4 cup sugar in a separate basin for 3 minutes, or until light in color.
One at a time, add the yolks, mixing constantly for about 2 minutes.
To the egg yolk mixture, add the milk, cake flour, baking powder, and vanilla extract. For about 2 minutes, or until smooth, beat the batter.
Fold a third of the meringue into the egg yolk mixture gently, then fold in the remaining meringue until thoroughly incorporated.
In a preheated 400 F oven, bake for 30 minutes, or until a toothpick inserted in the center comes out clean.
Remove the cake from the oven and cool for about 10 minutes in the pan before transferring to a cooling rack. Before icing, remove the parchment paper from the cake and allow it to cool.