Preheat and Prepare: Preheat the oven to 350°F (175°C). Grease a loaf pan (8x4 or 9x5 inches) with butter or oil, or line with parchment paper.
Mash the Bananas: Peel and mash the bananas in a large bowl using a fork or potato masher until smooth, with some chunks remaining.
Mix Dry Ingredients: In a small bowl, whisk together gluten-free flour, baking powder, baking soda, cinnamon, and salt.
Combine Wet Ingredients: In the large bowl with the mashed bananas, whisk in the eggs, sweetener (maple syrup, honey, or coconut sugar), melted butter or coconut oil, and vanilla extract until smooth.
Add Dry Ingredients: Gradually fold the dry ingredients into the wet ingredients, mixing gently until just combined. Be careful not to overmix. Add Walnuts: Gently fold in the chopped walnuts, making sure they’re evenly distributed in the batter.
Bake: Pour the batter into the prepared loaf pan and spread it out evenly.Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean. Cool: Remove the bread from the oven and let it cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.
Serve: Slice and enjoy your gluten-free banana bread with walnuts fresh or toasted with a bit of butter or spread.