Preheat oven to 350°F. Grease or spray with non-stick cooking spray a 9 x 5 inch loaf pan.
In the large bowl of a stand mixer, fitted with paddle attachment, cream the shortening and the sugar on medium speed until light and fluffy. Add eggs, one at a time, beating well after each addition. Add vanilla, cinnamon, sour cream. bananas and orange peel (if using). Beat on low speed to combine.
In medium bowl, whisk together flour, baking soda and salt.
Add dry ingredients to the banana mixture, beating on medium speed for one minute. Scrape down bowl as needed.
Spread into prepared pan. Bake on center rack of oven for 1 hour to 1 hour and 15 minutes, or until toothpick inserted in center comes out clean.
Allow to cool for 10 minutes on a wire rack. Remove from the pan and cool completely on the wire rack.