1/2 cup finely chopped semi-sweet chocolate pieces
Preheat oven to 350 F. Grease and flour a 13x9x2 baking pan, or two 9" round baking pans.
Combine all ingredients (except chopped chocolate) into a large mixer bowl. Blend 30 seconds on low speed, then beat on high for 3 minutes. Fold in chocolate. Bake 40-45 minutes.