To a mixer, add mashed bananas, sugar, the egg, oil and vanilla. Mix until well combined.
To a separate bowl, whisk together the gluten free flour, baking soda and salt.
Gradually add the flour mixture to the mixer of wet ingredients until well combined.
Add chocolate chips. Using a spatula, mix until they are evenly distributed.
Line a standard 12-cup muffin tin with paper liners. Scoop batter with either a ladle or cookie scoop. Sprinkle additional chocolate chips on each muffin cup.
Bake for 15-25 minutes* or until a toothpick inserted in the center comes out clean. Remove and let cool for 5 minutes before moving to a cooling rack.
Notes
*If you're using a jumbo muffin or loaf pan, the cook time will be longer