Preparation: Preheat your oven to 350°F (175°C). Grease a loaf pan and line it with parchment paper for easy removal.
Brown the Butter: In a saucepan over medium heat, melt the butter. Continue cooking, swirling the pan occasionally, until the butter turns golden brown and releases a nutty aroma. Remove from heat and let it cool for a few minutes.
Mix Wet Ingredients: In a mixing bowl, combine the mashed bananas, browned butter, maple syrup, eggs, and vanilla extract. Mix until well combined.
Combine Dry Ingredients: In a separate bowl, whisk together the flour, baking soda, baking powder, and salt.
Combine Mixtures: Gradually add the dry ingredients into the wet ingredients, mixing until just combined. Do not overmix. If using nuts, gently fold them into the batter.
Bake: Pour the batter into the prepared loaf pan. Smooth the top with a spatula. Bake in the preheated oven for 50-60 minutes or until a toothpick inserted into the center comes out clean.
Cool: Once baked, remove the banana bread from the oven and let it cool in the pan for 10-15 minutes. Then transfer it to a wire rack to cool completely before slicing.