Beat first 4 ingredients at medium speed with an electric mixer until blended.
Combine flour and next 4 ingredients; add to butter mixture alternately with buttermilk, beginning and ending with flour mixture. Beat at low speed until blended after each addition. Add egg whites, and beat at medium speed 1 minute. Spray a 9-inch pieplate with cooking spray 5 seconds. Pour batter into pieplate.
Bake at 350° for 25 to 30 minutes or until a wooden pick inserted in center comes out clean. Garnish, if desired.
Note: Spray measuring spoon with cooking spray 1 second before measuring molasses.