Banana Sheet Cake

Ingredients: 2½ cups flour 1½ cups sugar 1¼ teaspoons baking powder 1¼ teaspoons baking soda 1 teaspoon salt 3/4 cup margarine 2/3 cup buttermilk or sour milk 1¼ cups bananas 2 eggs 1/2 cup nuts Frosting: 8 oz. cream cheese 3/4 stick oleo 4 cups powdered sugar 1½ cup nuts Directions:  Mix dry ingredients. Cream sugar, shortening and bananas, then add dry ingredients. Pour in a 10" x 15" pan. Bake at 350° F. until toothpick comes out clean. Cool and frost. Do not over-bake.