In a mixing bowl, whisk together the flour, sugar, baking powder, and salt.
In another bowl, mix the milk, egg, and melted butter.
Pour the wet ingredients into the dry ingredients and stir until just combined. Fold in the mashed bananas.
Heat a frying pan over medium heat and lightly grease it. Pour ¼ cup of batter for each pancake. Cook until bubbles form on the surface, then flip and cook until golden brown.