In a mixing bowl, whisk together the flour, sugar, baking powder, baking soda, and salt.
In another bowl, mix the milk, egg, and melted butter. Add the mashed bananas and stir until combined.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix.
Heat a frying pan over medium heat and grease lightly with butter or oil. Pour ¼ cup of batter for each pancake. Cook until bubbles form on the surface, then flip and cook until golden brown.