Sift together flour, baking powder, baking soda, and salt in a large bowl.

In another bowl, mix banana, brown sugar, cinnamon, vanilla, egg, and milk.

Stir banana mixture into flour mixture until just blended.

Preheat griddle or frying pan over medium heat and spray with nonstick spray, if necessary.

Right before cooking pancakes, mix melted butter into the batter.

Pour batter by 1/3-cupfulls onto the griddle. Cook until sides are dry and bubbles have formed on top, then flip over. Cook until pancakes have puffed slightly and are golden brown. Repeat with remaining batter, adjusting heat on griddle as necessary. Serve with additional banana slices, if desired, and maple syrup.