Step 1
Preheat oven to 375 degrees F (190 degrees C). Grease 10 muffin cups lightly, or you can line with muffin papers.
Step 2
Mix one and half cups flour, baking soda, baking powder and salt in a large bowl together. In another bowl, add bananas, sugar, egg and melted butter together. Then add the banana mixture into the flour mixture, stir it until it moistened. Add Spoon batter into prepared muffin cups.
Step 3
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.
Step 4
Bake in preheated oven for 18 to 20 minutes, until a toothpick inserted into center of a muffin comes out clean.
