Muffin:

1 ½ Cups all-purpose flour
1 teaspoon baking soda
1 teaspoon baking powder
½ teaspoon salt
¼ teaspoon cinnamon (or spice blend, cinnamon, nutmeg, cloves)3 bananas, mashed
½ cup white sugar
1 egg lightly beaten
1/3 cup oil
1/2 cup chopped walnuts (optional)

Muffin Topping

1/3 cup packed brown sugar
¼ teaspoon cinnamon (or spice blend, cinnamon, nutmeg, cloves)
2 Tablespoons all-purpose flour
¼ cup oats (optional)
¼ cup chopped walnuts (optional)
2 Tablespoons butter