Separate the egg whites and allow them to sit at room temperature for at least 30 minutes.
Preheat the oven to 350. In the bowl of a food processor, process the flour, cornstarch and powdered sugar together until smooth, about 30 seconds. Set aside.
Process the granulated sugar slightly, about 5-7 pulses. You don't want to turn it into powdered sugar, just a little finer than it is normally. Set aside.
Place the egg whites in the bowl of a stand mixer. Beat on high until starting to foam then add the salt and cream of tartar.
Add the vanilla and almond extract and continue whipping on high speed.
Add the granulated sugar slowly, about 1 tablespoon at a time to the egg whites while they are whipping.Continue whipping until stiff peaks form.
Slowly fold in the dry ingredients ⅓ at a time with a spatula. Do this carefully and slowly so you don't deflate the egg whites. (This is the key to good angel food cake.) Scoop into a ungreased 10-inch round pan.
Bake at 350 for about 35-40 minutes until lightly golden. Immediately invert pan onto a cooling rack when you remove it from the oven. Cool completely then run a knife along the edges of the pan and carefully plate the cake. Enjoy!