Preheat the oven to 350 degrees.
Line 12 cupcake tins with paper liner or grease well.
Using a hand mixer or a stand mixer fitted with the paddle attachment, cream shortening and sugar for 1-2 minutes or until fluffy. Scrape down the bowl once complete.
Break the bananas into a few pieces and add a little at a time to the creamed butter and sugar. Beat well between each addition to mash the bananas. You can also mash the bananas ahead of time in a gallon bag.
Add in eggs, sour cream and vanilla extract. Mix until combined. Scrape down the bowl once complete.
In a separate bowl, whisk together dry ingredients (flour, baking soda, cinnamon, salt).
Add dry ingredients to wet ingredients in 2-3 portions, mix until combined.
Use a spoon or a cookie dough scoop to spoon the batter into the muffin tins. Fill ¾ full.
Bake for 20-25 minutes or until a toothpick comes out clean. Allow them to cool to room temperature before frosting.