Preheat your oven to 350 °F and prepare an 8-inch loaf pan by lining it with parchment paper. This ensures easy removal of the bread later and creates a beautiful presentation.
In a small saucepan, melt the butter over medium heat. Watch as it transforms to a lovely golden brown, which will take about 3 to 5 minutes. Make sure to swirl the pan occasionally to promote even cooking. Once it reaches a toasty color, remove it from the heat and let it cool slightly.
In a medium mixing bowl, combine the blanched almond flour, coconut flour, baking powder, cinnamon, and sea salt. Whisk everything together thoroughly to mix the dry ingredients.
In a separate bowl, mash the ripe bananas until smooth. Add the eggs, maple sugar, vanilla extract, and the cooled brown butter to the bananas. Whisk until fully combined and creamy.
Now, pour the wet ingredients into the dry mixture. Stir gently until just combined; avoid overmixing, as this can affect the bread's texture. You want a few lumps to remain.
If you're using them, fold in the chopped walnuts and dark chocolate chunks. This is where the magic happens, as the chocolate melts into gooey pockets of sweetness in every bite!
Transfer the batter into the prepared loaf pan. Use a spatula to smooth out the top, and if desired, sprinkle some extra chocolate chips on top for added decadence.
Place the loaf pan in the preheated oven and bake for 40 to 45 minutes. Keep an eye on it; you’ll know it’s done when a toothpick inserted into the center comes out clean.
Once baked, remove the loaf from the oven and let it cool in the pan for about 10 minutes. Then, transfer it to a wire rack to cool completely before slicing into it. The aroma will have your family running to the kitchen!