Banana Crumb Muffins

We love banana bread, so these muffins make it quick in the morning. Sometimes I put the crumb topping on it, but usually not. It is plenty sweet and tasty without it.
Muffins
1 1/2 cups whole wheat or all purpose flour
1 tsp baking soda
1 tsp baking powder
1/4 tsp salt
3 bananas, mashed
1/2 cup sugar
1 egg, lightly beaten
1/3 cup butter, melted
Topping
1/3 cup packed brown sugar
2 Tbl flour
1/8 tsp cinnamon
1 Tbl butter
1. Preheat oven to 375 degrees. Lightly grease muffin cups or line with muffin papers.
2. In a large bowl, mix together flour, soda, baking powder, and salt. In another bowl, beat together bananas, sugar, egg and melted butter. Stir the banana mixture into the flour mixture just until moistened. Spoon batter into prepared muffin cups.
3. In a small bowl, mix together brown sugar, 2 Tbl flour and cinnamon. Cut in 1 Tbl butter until mixture resembles coarse cornmeal. Sprinkle topping over muffins.
4. Bake for 18-20 minutes