1. preheat oven to 350º
2. Combine sugar and butter in bowl; beat with mixer at low speed till blended. Add banana, milk, sour cream and egg whites; beat well.
3.Lightly spoon in flour into dry measuring cup. Level with a knife.Combine flour, baking soda and salt and stir well.
4 Add dry ingredients to other ingredients beating until blended.
5 to make a 9 inch loaf, spoon battering 9X5 inch loaf sprayed with cooking spray.
6. Bake 1 hour and 10 minutes until a wooden toothpick inserted in center, comes out clean.
7. Cool completely on wire rack.
Possibilities: Add a a cup of chocolate chips to batter or crushed walnuts or both.