In a mixing bowl, whisk together the flour, brown sugar, baking powder, baking soda, and salt.
In another bowl, combine the buttermilk, egg, melted butter, mashed banana, and vanilla extract.
Pour the wet ingredients into the dry ingredients and stir until just combined; do not overmix.
Heat a non-stick skillet or griddle over medium heat and lightly grease with butter or oil.
Pour about 1/4 cup of batter for each pancake onto the skillet.
Cook until bubbles form on the surface, about 2-3 minutes, then flip and cook for another 1-2 minutes until golden brown.
Serve warm with maple syrup, sliced bananas, or your favorite toppings.