Combine first 7 ingredients in a medium bowl; cut in margarine with a pastry blender until mixture resembles coarse meal. Combine banana, coffee and milk; stir well. Add to flour mixture, stirring just until dry ingredients are moistened.
Sprinkle 1 TBL flour over work surface. Turn dough out onto floured surface, and knead 3 to 4 times. Roll dough to ½-inch thickness; cut with a 2-inch biscuit cutter. Transfer to a baking sheet coated with cooking spray. Bake at 425 degrees for 8 to 10 minutes or until lightly browned.