01 - Preheat oven to 350°F. Grease a 9×5-inch loaf pan with butter or cooking spray, or line with parchment paper for easy removal.
02 - In a large mixing bowl, whisk together the mashed bananas, melted butter, granulated sugar, brown sugar, eggs, and vanilla extract until smooth and well incorporated.
03 - In a separate medium bowl, whisk together the all-purpose flour, baking soda, baking powder, and salt until evenly distributed.
04 - Add the dry ingredients to the wet mixture. Using a spatula, gently fold until just combined—stop as soon as no dry flour remains visible. Avoid overmixing to prevent dense bread.
05 - Fold in the semisweet chocolate chips and chopped walnuts or pecans if using, distributing evenly throughout the batter.
06 - Pour the batter into the prepared loaf pan, spreading evenly with a spatula. Sprinkle additional chocolate chips across the top for garnish if desired.
07 - Bake for 50 to 60 minutes, rotating the pan halfway through for even browning. The bread is done when a toothpick inserted in the center comes out with just a few moist crumbs.
08 - Let the bread cool in the pan for 10 minutes to set. Carefully remove from the pan and transfer to a wire rack. Cool completely before slicing into 8 to 10 servings.