Prep the pan and oven. Heat the oven to 350°F (175°C).
Grease a 9x5-inch loaf pan or line it with parchment, leaving a little overhang for easy lifting.
Mash the bananas. In a large bowl, mash the bananas until mostly smooth with a few small lumps left for texture.
Whisk in the wet ingredients. Add eggs, melted coconut oil or butter, brown sugar, and vanilla. Whisk until the mixture is glossy and well combined.
Combine the dry ingredients. In a separate bowl, whisk the all-purpose flour, pumpkin flour, baking soda, baking powder, salt, cinnamon, and nutmeg.
Bring it together. Add the dry ingredients to the wet and gently fold with a spatula. Stop as soon as there are no dry streaks.
The batter will be thick but spreadable.
Add mix-ins. Fold in nuts and chocolate chips if using. Keep the stirring light so the loaf stays tender.
Fill the pan. Scrape the batter into the prepared pan and smooth the top. For a pretty finish, you can sprinkle a few nuts or a pinch of sugar on top.
Bake. Bake for 50–60 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs.
If the top browns too fast, tent it loosely with foil in the last 10–15 minutes.
Cool. Let the loaf cool in the pan for 15 minutes, then lift it out and cool completely on a rack before slicing. This helps set the crumb so slices are neat.
Serve. Enjoy plain, with a smear of butter, or a drizzle of honey. It’s also great slightly toasted the next day.