Ultimate Banana Muffins

Name: Ultimate Banana Muffins
Prep time: 15 min
Cook time: 20 min
Total time: 35 min
Cuisine: American
Ingredients: 1.5 cups all-purpose flour; 1 teaspoon baking powder; 1 teaspoon baking soda; 1 teaspoon ground cinnamon; 0.5 teaspoon salt; 1 pinch ground nutmeg; 3 bananas (ripe or very ripe work best); 0.5 cup white sugar; 0.33333334326744 cup butter, melted; 0.25 cup lightly packed brown sugar; 1 large egg; 1 teaspoon vanilla extract; 0.25 cup chopped walnuts