Preheat oven to 350F and grease a loaf pan with vegan butter.
Melt stick of butter and add to a bowl. Add in mashed bananas, vanilla extract and egg, mix well.
In a second bowl whisk together gluten-free flour, sugar, baking soda, salt and cinnamon. Add to wet ingredients and mix until well combined.
Pour batter into your prepared loaf pan and bake for 40-50 minutes or until a toothpick comes out of the center clean.
Let sit for 5 minutes before indulging! ENJOY :)