Preheat the oven to 350°F (175°C). Prepare a loaf pan by greasing it or lining it with parchment paper.
In a bowl, combine the flour, baking soda, cream of tartar, and salt. Mix well and set aside.
In a separate bowl, cream the shortening and sugar together until well combined.
Add the eggs and mix until incorporated.
Alternately fold the dry ingredients, mashed banana, and cranberry sauce into the creamed mixture, ending with the cranberry sauce.
Gently fold in the chopped nuts until evenly distributed.
Transfer the batter to the prepared loaf pan and spread it evenly.
Bake for approximately 1 hour, checking toward the end of baking to avoid overbaking. A toothpick inserted into the center should come out without wet batter.
Allow the loaf to cool completely before slicing for cleaner, thinner pieces.