Cream shortening and sugar until fluffy. Add eggs, one at a time, beating well after each addition. Stir in banana and vanilla. Sift dry ingredients together and add to banana mixture. Mix well. Pour into greased loaf pan or 9"x9"x2" pan. Bake at 350°F for 30 to 35 minutes. Note: 1/2 cup chopped nuts can be added if desired.