Sift flour, salt and baking powder together 3 times. Beat egg whites until stiff but not dry. Whip cream until stiff and fold in egg whites. Add sugar gradually and mix well. Add flour mixture alternately with water in small amounts. Add flavoring and blend thoroughly. Divide batter between two 8-inch cake pans that have been lined with waxed paper. Bake at 350F for 25-30 minutes. Cool on wire rack 10 minutes; remove from pans and allow to cool completely. Frost with Mock Whipped Cream Frosting.