Preheat your oven to 350°F.

Place the granulated sugar in a food processor and pulse for about 2 minutes until it becomes superfine.

Sift together half of the superfine sugar with the salt and cake flour; set the remaining sugar aside.

In the bowl of a stand mixer fitted with the whisk attachment, combine the egg whites, warm water, vanilla extract, almond extract, and cream of tartar. Mix on low speed for about 1 minute.

With the mixer running on medium speed, gradually sift in the reserved superfine sugar and continue beating until the meringue reaches medium peaks.

When the peaks are medium, sift a portion of the flour mixture over the foam and gently fold it in using a spatula.

Repeat folding in the remaining flour mixture until it is fully incorporated.

Carefully spoon the batter into an ungreased tube pan.

Bake for 35 minutes, then test for doneness by inserting a wooden skewer halfway between the inner and outer wall; it should come out dry.

Immediately invert the pan onto a cooling rack and let it cool upside down for at least 1 hour before removing the cake.