Line two 10-inch round cake pans with parchment paper and lightly spray with nonstick cooking spray. Set aside.
In a medium bowl, sift together the flour, baking powder, and corn starch. Set aside.
In the bowl of a stand mixer fitted with the whisk attachment, beat the eggs on high speed until foamy.
Gradually add the granulated sugar while continuing to beat until the mixture becomes thick, pale, and airy (about 7–10 minutes).
Once the mixture reaches ribbon stage (falls like ribbons when lifted), beat in the vanilla extract.
Carefully fold in the sifted dry ingredients with a large whisk or spatula. Be gentle to preserve the air in the batter.
Evenly divide the batter between the prepared cake pans.
Bake at 350°F for 20 minutes, or until a toothpick inserted in the center comes out clean. Let cakes cool completely in the pans, then carefully remove and cool further on wire racks.
Once fully cooled (preferably chilled overnight), slice each cake horizontally into 2 thin layers using a serrated knife, for a total of 4 cake layers.