Preheat oven to 350° F. Grease a 9"x5" loaf pan with shortening or nonstick cooking spray.
In a medium mixing bowl, whisk together the gluten free flour blend, baking soda, and salt until combined.
In a large mixing bowl, add the mashed bananas, peanut butter and melted butter and stir until combined Add the brown sugar, egg, and vanilla and stir until smooth.
Add the dry ingredients to the wet ingredients and stir until just combined.
Transfer the batter to the prepared pan.
Bake for 55-60 minutes, or until a wooden pick inserted into the center comes out clean.
Cool the bread in the pan for 10 minutes. Remove the bread from the pan and allow to cool completely on a wire rack.
Notes
Grease or use non-stick cooking spray all around the inside of the loaf pan. Doing this will prevent the bread from sticking to the pan.
Be sure to use really ripe bananas with brown spots on the peels. Under ripe bananas won’t add enough sweetness to the bread.
Check the bread with a cake tester or wooden pick before removing it from the oven. Test the bread in the middle of the loaf to ensure the thickest part of the bread is done.