Preheat your oven to 350°F and generously spray a 9x5x3-inch loaf pan with nonstick cooking spray. Set it aside.

In a medium bowl, whisk together the flour, cocoa powder, and baking soda until well combined. This helps make sure everything bakes evenly.

In a large bowl, add the mashed bananas, softened butter, granulated sugar, brown sugar, egg, vanilla extract, and sour cream. Mix until smooth and creamy.

Gradually fold the dry ingredients into the wet ingredients, stirring just until the batter comes together. Don’t overmix—stop as soon as you no longer see dry flour.

Pour the batter into the prepared loaf pan and smooth out the top. Sprinkle an extra handful of chocolate chips over the batter for that bakery-style finish.

Bake for 50 to 60 minutes, or until a toothpick inserted into the center comes out mostly clean with a few moist crumbs.

Remove the bread from the oven and let it cool completely before slicing. Serve, enjoy, and try not to eat the whole loaf in one sitting!