Place egg whites in a large bowl; let stand at room temperature for 30 minutes. Sift powdered sugar and flour together twice; set aside.
Add cream of tarter, extracts and salt to egg whites; beat on medium speed until soft peaks form. Gradually add sugar, about 2 tablespoons at a time, beating on high until stiff glossy peaks form and sugar is dissolved. Gradually fold in flour mixture, about 1/2 cups at a time.
Gently spoon into an ungreased 10-in. tube pan. Cut through the batter with a knife to remove air pockets. Bake on the lowest oven rack at 350 degrees for 40-45 minutes or until lightly browned and entire top appears dry. Immediately invert pan; cool competely, about 1 hour.
Run a knife around side and center tube of pan. Remove cake to a serving plate. Drizzle with glaze or frost if desired.