In a food processor, process sugar for 2 minutes to make it superfine
Sift half of the sugar with the cake flour and salt and set aside.
Separate egg whites and yolks. Add whites to stand mixer or large bowl and whisk or mix on medium with the whisk attachment. Add in water, extract, and cream of tartar. After a few minutes of mixing, slowly add in the other half of the sugar not sifted with the cake flour.
Once the whites are holding medium peaks, remove from mixer. Dust the tops of the whites with about 1/3 of the flour mixture and carefully fold the flour into the whites using a flat spatula. Don't stir the flour in or you'll break up all the air bubbles. Work around the edges of the bowl folding the flour into the whites.
Continue dusting with flour and folding until all the flour is just incorporated.
Add batter to a ungreased Bundt or tube pan. Bake for 35 minutes and check for doneness with a wooden toothpick.
Cool cake upside down on a wire rack for about an hour. Then carefully remove it by sliding a knife around the outside. Serve drizzled with chocolate sauce, fresh berries and whipped cream, if desired.