1. Preheat your oven to 350°F and grease your 9×5-inch loaf pan with butter or nonstick spray. Line the bottom with parchment paper for easy removal.

2. Mash the bananas with a fork in a large mixing bowl until mostly smooth. Add the sour cream and melted butter, then whisk together until well combined.

3. Whisk in the sugar, eggs, and vanilla extract until the mixture is smooth and slightly lighter in color, about 30 seconds.

4. Add the flour, baking soda, salt, and cinnamon directly to the wet ingredients. Gently fold with a rubber spatula until just combined with a few flour streaks remaining.

5. Fold in nuts or chocolate chips if using with just 2-3 gentle strokes. Save a tablespoon to sprinkle on top.

6. Pour the batter into your prepared pan and smooth the top. Bake for 60-70 minutes, until a toothpick inserted in the center comes out with just a few moist crumbs.

7. Cool in the pan for 15 minutes, then turn out onto a cooling rack. Let it cool for at least 30 more minutes before slicing.