Banana-Bran Muffins

1 cup all-purpose unbleached flour
1 cup wheat bran
1 tsp. baking soda
1/2 tsp. salt
1/2 cup chopped walnuts (optional)
1 cup mashed ripe banana (two large bananas)
1/2 cup butter, melted
1/2 cup natural sugar
1 egg

In a medium bowl combine the flour, bran, baking soda, salt and nuts. Set aside. In another bowl beat together the banana, butter, sugar, and egg until completely mixed. Add the dry ingredients and stir just until blended. Spoon into greased muffin tins, filling about three-quarters full. Bake at 375 for 15-20 minutes or until done. Yield: 12 muffins