Banana Crumb Muffins

We've begun to overbuy on bananas lately so instead of repeatedly making banana bread, I've been on the hunt for different banana recipes.  I made Banana Cupcakes with Nutella Frosting last week.  I wonder if I'll run out of banana recipes...  Anyway, I actually preferred these cupcakes over last week's.  The nutella frosting was a little rich for me (I cannot believe I just said that!) but I guess when eat a lot of bland food, anything is too rich for you ;)

1 1/2 c all purpose flour
1 tsp baking soda
1 tsp baking powder
1/2 tsp salt
3 bananas, mashed
3/4 c sugar
1 egg, lightly beaten
1 tsp vanilla
5 tbsp butter, melted
1/3 c packed brown sugar
2 tbsp all purpose flour
1/4 tsp cinnamon
1 tbsp butter, softened

Preheat oven to 375 F.  Lightly grease 10 muffin cups or line with muffin papers.  In a large bowl, combine flour, baking soda, baking powder, and salt.  In another bowl, beat together bananas, egg, sugar, vanilla, and melted butter.  Stir banana mixture into flour mixture until moistened.  Spoon batter into prepared muffin cups.  Fill to top.  In a small bowl, mix brown sugar, 2 tbsp flour, and cinnamon.  Cut in 1 tbsp softened butter until it resembles a coarse cornmeal type mixture.  Sprinkle topping generously over muffin tops.  Bake for 18-20 minutes or until center of muffin comes out clean.