advanced—serves 16

Use some of your leftover yolks for the curd recipe

13/4 cups superfine sugar or quick-dissolve sugar
1/4 tsp. salt
1 cup cake flour
12 egg whites (at room temperature)
1/3 cup warm water
1 tsp. vanilla extract
11/2 tsp. cream of tartar

Preheat oven to 350°. Sift 1 cup superfine sugar (reserve remaining 3/4 cup sugar), salt, and cake flour together into a mixing bowl. Set aside.

With a mixer, whisk egg whites, water, vanilla, and cream of tartar. Slowly sift reserved ¾ cup sugar into the egg white mixture, beating continuously at medium speed. Once you have achieved medium peaks, sift in enough of the flour mixture to dust the top of the foam.
Using a spatula, fold the egg and flour mixture together. Repeat until all of the flour mixture is in the egg white mixture, making it thick and fluffy.

Carefully spoon mixture into an ungreased tube pan. Bake for 35 minutes before checking for doneness with a wooden skewer. Cool the cake upside down on cooling rack for at least an hour before removing from pan. Enjoy