Banana Blueberry Muffins with Crumb Topping

Name: Banana Blueberry Muffins with Crumb Topping
Prep time: 5 min
Cook time: 17 min
Total time: 22 min
Cuisine: American
Ingredients: 2 ¼ cups all-purpose flour ((270 grams)); 1 tablespoon baking powder; ¾ teaspoon baking soda; ½ teaspoon ground cinnamon; ½ teaspoon salt; ½ cup butter (melted); ¾ cup brown sugar ((156 grams)); 2 large eggs; 2 teaspoons vanilla extract; 3 to 4 bananas (1-½ cups mashed); 2 cups fresh or frozen blueberries; ¾ cup all-purpose flour ((90 grams)); ½ cup granulated sugar ((100 grams)); 1 teaspoon ground cinnamon; 4 tablespoons butter (melted)