Preheat the oven to 400℉.
In a bowl, mash the bananas then whisk in the egg, vanilla extract, butter and then the sugar. In a separate bowl, mix the the gluten-free flour, salt and baking powder. Combine the dry and wet ingredients.
Now, fold in the chocolate chips. Scoop the batter into a muffin pan with liners. Then, place in the oven for 15-20 minutes.
When the muffins are finished, allow them to cool before serving.