Preheat your oven to 350 degrees F. Spray a 9x5 inch loaf pan with nonstick spray, or line it with parchment paper.

If you plan to add nuts, toast them now. Spread 1/2 or 3/4 cup chopped nuts on a dry baking sheet. Bake at 350 for 5-7 minutes, stirring every 2 minutes. They are done when fragrant. Set aside to cool.

In a large bowl or stand mixer, beat the softened butter until smooth. Add the brown and granulated sugars and cream together for about 2 minutes until fluffy, scraping the sides and bottom of the bowl.

Add the eggs and vanilla extract. Beat until well combined, scraping the sides again.

In a small bowl, mash the ripe bananas with a fork or potato masher until you have about 1 cup. Add the mashed bananas to the butter mixture and stir until combined.

Add the flour to the bowl but do not stir yet. Blend the oats in a blender or food processor until it turns into a powder. Add this oat flour to the bowl without stirring.

Use a small spoon to mix the baking soda, baking powder, and salt into the flour. Ensure there are no clumps.

If desired, add spices like cinnamon, cloves, and nutmeg for added flavor. Stir the dry ingredients into the wet ingredients until combined, scraping the sides and bottom.

Finally, fold in the sour cream and any nuts you want to include.

Pour the batter into the prepared loaf pan and smooth the top. Bake for 55-65 minutes. Check with a toothpick inserted in the center—if it comes out clean, it’s ready.

Let the bread cool for about 20 minutes on a cooling rack before slicing.