2/3 cup butter or margarine
1 1/3 cups granulated sugar
1 1/4 cups mashed ripe bananas
1 teaspoon baking soda
1/2 cup sour cream
1 teaspoon baking powder
2 eggs
2 3/4 cups all-purpose flour
1 teaspoon salt
1 cup chopped walnuts or pecans

Preheat oven to 350 degrees F. Grease and flour the bottom only of a 9 x 5-inch loaf pan.

Cream butter and sugar until light and fluffy. Add eggs and bananas until well blended. Sift dry ingredients and add alternately with sour cream to banana mixture, stirring just to blend. Stir in walnuts. Spoon batter into prepared loaf pan. Bake 1 hour and 15 minutes or until wooden pick comes out clean. Let stand in pan on rack 20 minutes.

Remove from pan. Cool. Wrap in aluminum foil. Loaf is improved if left to stand overnight. Store in refrigerator or freeze for 2 months.