1.Preheat oven to 350°F. Spray two 8 in. round pans with vegetable cooking spray.
2.In medium bowl, sift together flour, baking powder and salt; set aside. In large bowl, beat butter and sugar with electric mixer until light and fluffy; add vanilla and beat well. Add flour mixture to butter mixture alternately with milk and oil; beat well after each addition. In separate bowl, beat egg whites until stiff but not dry; gently fold into batter. Divide evenly into prepared pans.
3.Bake 32-36 minutes or until toothpick inserted in center of cake comes out clean. Cool 10 minutes in pan on rack; remove and cool completely before decorating.