Preheat oven to 350°F (175°C) and grease a loaf pan.
In a bowl, mix the gluten-free flour, baking soda, salt, and xanthan gum.
In another bowl, whisk together the melted coconut oil, mashed bananas, eggs, maple syrup, and vanilla extract.
Gradually combine the wet and dry ingredients, mixing until well incorporated.
Pour the batter into the greased loaf pan and smooth the top.
Bake for 50 minutes or until a toothpick inserted in the center comes out clean.
Remove from the oven and let cool in the pan for 10 minutes before transferring to a wire rack.
Slice and serve once completely cooled.