Silver Cake (White Cake)
["3 c. sifted cake flour", "1/2 c. butter", "1/2 tsp. lemon extract", "4 egg whites, stiffly beaten", "1 1/2 c. sugar", "1 c. milk", "2 tsp. baking powder"]
["Sift flour once; measure.", "Add baking powder and sift together three times.", "Cream butter thoroughly.", "Add sugar gradually and cream together until light and fluffy.", "Add flour alternately with milk, a small amount at a time.", "Beat after each addition until smooth.", "Add lemon extract.", "Fold in egg whites."]
["cake flour", "butter", "lemon extract", "egg whites", "sugar", "milk", "baking powder"]