Oven 325 degrees. Separate egg yolks from whites. In a large mixer bowl sift together cake or all-purpose flour, sugar, baking powder and 1 teaspoon salt; make a well in the center. Add oil, egg yolks, peel, vanilla and 3/4 cup cold water. Beat at low speed of electric mixer until combined, then on high speed about 5 minutes or until satin smooth. Thoroughly wash beaters.
In a large mixing bowl combine egg whites and cream of tartar; beat until stiff peaks form. Pour batter in a thin stream over surface of egg whites; fold in gently by hand. Pour into an ungreased 10 inch tube pan. Bake in a 325 degree oven 65-70 minutes. Invert; cool completely. Loosen cake form pan; remove. Serves 12.
I used 2 teaspoons grated orange peel. In the Fluffy White Frosting I used 1/2 teaspoon orange extract and 1/2 teaspoon vanilla.
