In a large bowl, combine dry ingredients.
Combine bananas, sugar, egg and butter, mix well.
Stir into dry ingredients just until moistened.
Fill greased or paper lined muffin pan.
Combine topping ingredients; sprinkle over muffins.
Bake at 375 degrees for 20-25 minutes or until muffins test done.
Cool 10 minutes before removing to a wire rack.