Preheat the oven to 350°.

Mix together the sugar, shortening, and eggs. (An electric mixer works best. )

(An electric mixer works best. )

Stir in the sour milk and mashed bananas.

In another bowl, mix together the flour, baking powder, baking soda, and salt and blend into the banana mixture.

Add the walnuts and stir to blend.

Pour the batter into a well-greased loaf pan.

Let stand for 20 minutes; then bake for 50 to 60 minutes.