Banana Crumb Muffins

From Allrecipes.com
For the muffins:
1 1/2 cups all-purpose flour
1 teaspoon baking soda
1 teaspoon baking powder
1/2 teaspoon salt
3 bananas, mashed
3/4 cup white sugar
1 egg, lightly beaten
½ teaspoon cinnamon
1/3 cup butter, melted
For the topping:
1/3 cup packed brown sugar
2 tablespoons all-purpose flour
1/8 teaspoon ground cinnamon
1 tablespoon butter

Preheat oven to 375°.  Lightly grease 10 *Mine made 11 muffin cups, or line with muffin papers.
In a large bowl, mix together 1 ½ cups flour, baking soda, baking powder and salt. In another bowl, beat together bananas, sugar, egg, cinnamon and melted butter. Stir the banana mixture into the flour mixture just until moistened. Spoon batter into prepared muffin cups.

In a small bowl, mix together brown sugar, 2 tablespoons flour and cinnamon. Cut in 1 tablespoon butter until mixture resembles coarse cornmeal. Sprinkle topping over muffins.

Bake in preheated oven for 18 to 20 minutes, until a toothpick inserted into center of a muffin comes out clean. Cool 15 minutes before removing from pan.