01 - Preheat oven to 350°F. Grease a 9x5-inch loaf pan and line with parchment paper, leaving an 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 blended.
03 - In a separate medium bowl, whisk together the all-purpose flour, baking soda, salt, and ground cinnamon until evenly distributed.
04 - Pour the dry ingredient mixture into the wet ingredients. Using a spatula, gently fold until just combined — a few streaks of flour are fine. Do not overmix, as this will make the bread tough.
05 - If using, fold in the chopped walnuts or pecans and chocolate chips with a few gentle strokes.
06 - Pour the batter into the prepared loaf pan and smooth the top evenly with a spatula. Tap the pan once on the counter to release any air bubbles.
07 - Bake on the center rack for 50 to 60 minutes, rotating the pan halfway through, until the top is deep golden brown and a toothpick inserted into the center comes out clean or with a few moist crumbs.
08 - Let the bread cool in the pan for 10 minutes, then use the parchment overhang to lift it out onto a wire rack. Cool completely before slicing into 8 even portions.