Preheat oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line with parchment paper.
Mash bananas in a large bowl until smooth.
Add wet ingredients: Whisk in eggs, maple syrup, oil, and vanilla.
Mix dry ingredients: In a separate bowl, combine gluten-free flour, baking soda, baking powder, salt, and cinnamon.
Combine: Gently fold dry ingredients into the wet mixture until just combined. Avoid overmixing.
Add-ins: Stir in walnuts or chocolate chips (if using).
Bake: Pour batter into the loaf pan and smooth the top. Bake for 50–60 minutes, or until a toothpick inserted comes out clean.
Cool: Let it rest in the pan for 10 minutes, then transfer to a wire rack to cool completely.
