01 - Preheat oven to 350°F. Grease a 9x5-inch loaf pan and line with parchment paper, leaving an overhang on the 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 - Pour the dry ingredient mixture into the wet ingredients. Gently fold together using a spatula until just combined. Do not overmix, as this will produce a dense, tough loaf.
05 - If desired, gently fold chopped nuts or chocolate chips into the batter until evenly dispersed.
06 - Pour the batter into the prepared loaf pan and smooth the top with a spatula to create an even surface.
07 - Bake on the center rack for 50 to 60 minutes, or until a toothpick inserted into the center of the loaf comes out clean or with a few moist crumbs attached.
08 - Allow the loaf to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing into even portions.