01 - Preheat oven to 350°F. Grease a 9x5-inch loaf pan and line with parchment paper, leaving overhang on the long sides for easy removal.
02 - In a large mixing bowl, whisk together the mashed bananas, eggs, melted butter, granulated sugar, brown sugar, and vanilla extract until smooth and well incorporated.
03 - In a separate medium bowl, whisk together the all-purpose flour, baking soda, salt, and ground cinnamon until evenly distributed.
04 - Add the dry ingredient mixture to the wet ingredients and fold gently with a spatula until just combined. Avoid overmixing to keep the bread tender.
05 - If using, fold the chopped nuts or chocolate chips into the batter with a few gentle strokes.
06 - Pour the batter into the prepared loaf pan and smooth the top evenly with a spatula.
07 - Bake on the center rack for 50 to 60 minutes, rotating the pan halfway through, until a toothpick inserted into the center comes out clean or with a few moist crumbs.
08 - Allow the bread to cool in the pan for 10 minutes, then lift it out using the parchment overhang and transfer to a wire rack to cool completely before slicing.