Prep your pan and oven: Heat the oven to 350°F (175°C). Grease a 9x5-inch loaf pan and line it with a parchment sling for easy removal.

Mash the bananas: In a large bowl, mash the ripe bananas with a fork until mostly smooth with a few small lumps. You should have about 1 1/4 to 1 1/2 cups.

Whisk in the wet ingredients: Add the eggs, oil (or melted butter), vanilla, granulated sugar, and brown sugar. Whisk until well combined and glossy.

Mix the dry ingredients separately: In a medium bowl, whisk the gluten-free flour, baking soda, baking powder, salt, and cinnamon. This helps distribute the leavening evenly.

Combine gently: Add the dry ingredients to the wet mixture. Stir with a spatula just until no dry streaks remain. Do not overmix. If using add-ins, fold them in now.

Rest the batter briefly: Let the batter sit in the bowl for 5–8 minutes. This short rest hydrates the gluten-free flour and improves the crumb.

Fill the pan: Scrape the batter into the prepared loaf pan. Smooth the top and, if you like, sprinkle a little sugar or a few nuts on top for crunch.

Bake: Place on the center rack and bake for 50–65 minutes. Start checking at 50 minutes. It’s done when a toothpick inserted in the center comes out mostly clean with a few moist crumbs.

Cool properly: Let the loaf cool in the pan for 10–15 minutes. Lift it out using the parchment and place on a wire rack to cool for at least 45 minutes before slicing.

Slice and serve: Use a serrated knife for clean slices. Enjoy warm or at room temperature, plain or with a little butter.