Like with all baking recipes, but especially here, I highly recommend measuring by weight rather than volume. This proves especially useful when measuring the egg whites; you might find, as I did, that you need 13 egg whites, not 12, to yield 15 ounces. Do not use unbleached cake flour,
the cake will not rise properly. Do not be tempted to use a nonstick tube pan, the cake will not rise properly, and may slide out once inverted to cool, compressing the cake. Serve with whatever sort of berries look best at the market (or your favorite type).