Place egg whites in a large mixing bowl. Beat with wire whisk attachment of mixer on high speed until all egg whites are foamy. Add cream of tartar, salt and flavorings.

Beat eggs until stiff enough to hold stiff peaks but not until dry.

Add sugar, 2 tablespoons at a time, while continuing to beat on high speed until sugar is just blended.

Sift flour-sugar mixture over egg-white mixture about 1/4 cup at a time.

Using a silicone spatula, fold in gently but thoroughly after each addition.

Pour batter into an ungreased 10x4-inch tube pan. Smooth top of batter evenly in pan with a wet spatula.

Bake in a preheated 350°F oven for 40-45 minutes. (Cake will not bake in this time if your oven is not preheated for 15 minutes before putting cake in oven.)

Invert pan and cool cake in pan for 1 hour upside down, or until completely cold before removing the cake. Insert a dull knife along sides to free cake if cake is still attached after cooling.

Makes one 10-inch tube cake.

Serve with fruit, fruit syrups, whipped cream, rum sauce, etc. Angel cake is a wonderful foundation for assembled desserts; cut the cake and fill a glass dish with layers of angel cake, fruit and cream and refrigerate until set.

Heat butter until melted. Stir in powdered sugar, vanilla and water. Stir all ingredients until smooth.