Preheat and prepare the pan: Heat the oven to 350°F (175°C).
Grease a 9x5-inch loaf pan and line it with a parchment sling for easy removal.
Whisk the dry ingredients: In a medium bowl, whisk the flour, baking soda, baking powder, salt, and cinnamon until combined. This helps prevent clumps and ensures even rise.
Mash the bananas: In a large bowl, mash the ripe bananas with a fork until mostly smooth. A few small lumps are fine and add texture.
Mix the wet ingredients: Add the granulated sugar, brown sugar, oil (or melted butter), eggs, and vanilla to the bananas.
Whisk until the mixture looks smooth and glossy.
Combine wet and dry: Add the dry ingredients to the banana mixture. Stir gently with a spatula until you no longer see streaks of flour. Do not overmix or the bread can turn dense.
Fold in the chocolate chips: Reserve a small handful for the top if you like. Fold the rest into the batter with a few gentle turns.
Add nuts now if using.
Fill the pan: Scrape the batter into the prepared loaf pan and smooth the top. Sprinkle the reserved chips on top for a bakery-style look.
Bake: Place on the center rack and bake for 55–65 minutes. The bread is done when a toothpick inserted into the center comes out mostly clean, with a few moist crumbs.
Cool properly: Let the loaf cool in the pan for 10–15 minutes.
Then lift it out and cool on a wire rack for at least 1 hour before slicing. Cooling helps the crumb set and keeps slices from crumbling.
Slice and enjoy: Use a serrated knife for neat slices. Serve warm or at room temperature.