Prepare the Oven
Preheat your oven to 350°F (175°C). Grease two 9-inch loaf pans with baking spray or line them with parchment paper for easy removal.Cream Butter and Sugar
In a large mixing bowl, beat the softened butter and granulated sugar until light and fluffy. This usually takes about 3–4 minutes.Add Eggs and Vanilla
Beat in the eggs one at a time, then mix in the vanilla extract until everything is well incorporated.Mix in the Bananas
Add the mashed ripe bananas and continue mixing until smooth and creamy.Add Dry Ingredients
Stir in the flour, baking soda, kosher salt, and cinnamon. Mix only until no dry flour remains. Avoid overmixing to keep the bread tender.Fold in the Sour Cream
Gently fold the sour cream into the batter until evenly distributed. The batter should be thick and creamy.Fill the Pans
Divide the batter evenly between the two prepared loaf pans and smooth the tops.Bake
Bake for approximately 60 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs. Cool
Allow the loaves to cool in the pans for about 10 minutes before transferring them to a wire rack to cool completely.