2 cups sifted all-purpose flour
½ teaspoon baking powder
¾ teaspoon baking soda
½ teaspoon salt
½ cup shortening
1 ½ cups white sugar
2 eggs
1 teaspoon vanilla extract
¼ cup buttermilk
4 cups whipped heavy cream
Preheat oven to 350 degrees F (175 degrees C). Grease and flour two 9 inch layer cake pans. Sift together flour, baking powder, soda, and salt; set aside. In a large bowl, combine the shortening, sugar, eggs, and vanilla. Beat well. Blend in the buttermilk. Add sifted flour mixture alternately with mashed banana to the egg mixture while beating. Pour batter into prepared pans. Bake cake for 30 to 35 minutes. Remove from pans, and cool on wire racks. Fill and frost the cake with whipped cream.