Good-Cooking - Black Walnut Banana Muffins

Ingredients

• 3 bananas
• 1/2 cup granulated sugar
• 1/2 cup packed brown sugar
• 2 eggs
• 1/2 cup butter or margarine, melted
• 1 cup all-purpose flour
• 1 cup wheat flour
• 1 1/2 teaspoons baking soda
• 3 tablespoons buttermilk
• 2/3 cup black walnuts, chopped