1/2 c. butter, softened
1/3 c. granulated sugar
1/4 c. firmly packed dark brown sugar
1 lg. egg
1 1/4 c. mashed, ripe bananas
1/4 c. plain yogurt
1 c. whole wheat flour
1/2 c. all-purpose flour
1 tsp. baking soda
1/2 tsp. salt, optional

In a large bowl cream the butter. Add the sugars and beat mixture until it is light and fluffy. Add the egg and beat the mixture well.

In a small bowl combine well the bananas and the yogurt. Into another bowl sift together the whole wheat flour, all-purpose flour, baking soda and salt. Stir the banana mixture alternately with the flour mixture into the butter mixture and blend well.

Pour into a buttered loaf pan, 9 x 5 x 3 inches and bake at 350 degrees for 55 minutes. Let cool in pan for 10 minutes, turn out onto a rack and let cool completely.