Heat oven to 350F. Spray 9-inch square pan with nonstick cooking spray. In large bowl. beat sugar and margarine until well blended. Add bananas vanilla and egg; mix well. Lightly spoon flour into measuring cup;level off. Add flour, baking powder, baking soda and 2 teaspoons ginger to margarine mixture; mix until moistened. Add milk; mix well. Pour into sprayed pan. Bake at 350F. for 25 to 35 minutes or until toothpick inserted in center com es out clean. Cool slightly. In small bowl, combine all topping ingredients; mix gently. Cut cake into squ ares serve warm or cool topped with whipped topping mixture. Makes 9 servings.