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 banana.
Heat a frying pan over medium heat and grease lightly. Pour 1/4 cup of batter for each pancake. Cook until bubbles form on the surface, then flip and cook until golden brown.
Serve warm with your favorite toppings.
Notes:
For extra flavor, add a pinch of cinnamon to the batter.