ANGEL FOOD CAKE

Steps:

• Let egg whites stand in bowl of a standing electric mixer (see cooks' note) at room temperature about 1 hour before making cake. (They should be about 60°F, slightly below room temperature.)
• Set oven rack in lower third of oven and preheat oven to 350°F.
• Sift together confectioners sugar, flour, and salt onto a sheet of wax paper using a triple sifter or fine sieve.
• Beat whites in mixer until frothy. Add cream of tartar and beat at medium speed until they form soft peaks. Add granulated sugar gradually, beating, and continue beating just until whites are thickened and form soft, droopy peaks. Beat in vanilla.
• Sprinkle one fourth of sifted dry ingredients over whites and fold in with a rubber spatula gently but thoroughly. Fold in remaining dry ingredients, one third at a time.
• Gently pour batter evenly into ungreased tube pan and bake until top is light golden, cake retracts a bit from pan and springs back when touched lightly, and a tester comes out clean, 40 to 45 minutes. Invert pan onto neck of an empty wine bottle or a large metal funnel and cool cake completely.
• To remove cake from pan, run tip of a long, narrow knife between outer edge of cake and pan. Tilt cake pan on its side and gently tap bottom edge against counter. Rotate pan, tapping and turning a few more times, until cake appears free. Cover pan with a metal rack or cardboard round and invert, tapping pan firmly to loosen cake. Lift pan from cake. (It should come out beautifully, like a pillow taken out of a slipcover.)
• Slice cake with a serrated knife, using a sawing motion.