Topped with a brown sugar crumble, these moist banana muffins become extraordinary.
Preheat oven to 375 F. Line muffin tin with papers.
In a large bowl, mix dry ingredients together. Add bananas, sugar, egg and melted butter. Stir banana mixture into dry ingredients just until moistened. Spoon batter into prepared muffin cups.
Mix together brown sugar, flour and cinnamon. Cut in butter until mixture is crumbly. Sprinkle topping over muffins.
Bake in oven for 18-20 minutes, until toothpick inserted in center of muffin comes out clean.