04Mix mashed bananas, buttermilk and vanilla in another small bowl.
05Using an electric mixer, cream 1 1/4 cups sugar and shortening until fluffy. Add eggs 1 at a time, beating well after each adition. Add dry ingredients alternately with buttermilk mixture, mixing until just combined.
06Pour batter over bananas in pan. Bake until cake pulls away from sides of pan and a pick inserted into the center of cake comes out clean, about 1 hour and 5 minutes. Cool slightly.