In a large bowl, whisk together the flour, sugar, baking powder, baking soda, and salt.
In a separate medium bowl, combine the buttermilk, egg, melted butter, mashed bananas, and vanilla extract. Mix until well blended.
Pour the wet ingredients into the dry ingredients and gently stir until just combined. Do not overmix; some lumps are okay.
Heat a non-stick skillet or griddle over medium heat and lightly grease with butter or oil.
Pour 1/4 cup of batter onto the skillet for each pancake. Cook until bubbles form on the surface and the edges look set, about 2-3 minutes.
Flip the pancakes and cook for another 2 minutes or until golden brown and cooked through.
Remove pancakes from the skillet and keep warm. Repeat with remaining batter.
Serve warm with your favorite toppings such as maple syrup, sliced bananas, or nuts.