In a mixing bowl, whisk together flour, sugar, baking powder, baking soda, and salt.
In another bowl, combine milk, egg, and melted butter. Add mashed bananas and mix well.
Pour the wet ingredients into the dry ingredients and stir until just combined. Fold in chopped nuts.
Heat a skillet 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.