

Pour this completed cake batter into the prepared sheet pan, spreading it evenly.

Melt 2 tablespoons of butter and gently fold that into the cake mixture.Gently fold the egg white mixture into the cake mixture.In a separate bowl, use an electric mixer to beat the 3 egg whites with ¼ cup of granulated sugar, until stiff peaks form.In a large bowl, make the cake mixture by beating the almond flour, all-purpose flour, confectioner's sugar, 1 egg yolk, and the remaining 3 whole eggs, until well combined.Separate 3 eggs into 3 bowls as follows: all egg whites in the first bowl, 2 yolks in a second bowl, and the third yolk in a third bowl.Grease an 18×13-inch sheet pan and then line it with parchment paper or a Silpat mat, and lightly grease that as well.
