Grease a 9x5 loaf pan
In a large bowl, combine sugar and shortening and mix with electric mixer on high until light and fluffy. Add eggs, one at a time, beating well after each addition. Stir in the mashed bananas and lemon juice. Set aside. In another bowl, mix flour, baking powder and salt together. Carefully add in the banana mixture. Beat with mixer on medium for one minute to blend all together. Fold in the nuts, if using. Pour batter into loaf pan and bake for about 1 hour, or until cooked through and golden brown on top. Cool in pan for 15 minutes.
Can top with powdered sugar. Another option - add cup of chocolate chips to batter before baking.