1 hr 10 mins
– First line an 11 by 16 cookie sheet with parchment paper or buttered and floured waxed paper. Set aside. I am very generous with the buttering part to avoid any accidents with the batter.
– Combine the sugar, one teaspoon of vanilla and the yolks in a bowl and beat until it changes to a lighter color. Mix the flour and the baking powder in a separated container. All this is in preparation for the assembly of the batter.
– Beat the egg whites until they hold firm and form peaks. Now with a wire whisk add the egg yolk mixture and beat into the batter. Then using a rubber spatula place the flour-baking powder blend, in a folding manner. Go as fast as you can to avoid a grainy texture. Finally, fold in the melted butter.
– Pour into the prepared pan smoothing the batter evenly so that it touches all sides.