Combine flour, baking powder and salt. Combine milk and water. Add flour mixture to creamed mixture, alternately with milk mixture, beginning and ending with flour mixture. Mix well after each addition. Stir in flavoring.
Beat egg whites (at room temp.) until soft peaks form and then fold into the batter.
Pour into 3 greased and floured 9 inch round cake pans.
Bake at 350° for 25 minutes or until a wooden pick inserted into the center comes out clean. Cool in pans 10 minutes before removing the layers to cool completely.