In a large bowl, combine flour, baking powder, salt and cinnamon. In a separate bowl, mash banana with a fork, add milk, egg whites, oil and vanilla, stir to combine. Pour wet ingredients into the dry. Stir with a spoon until there are no more dry spots. Don't over-mix. Stir in nuts, if desired.
Heat a griddle or skillet over medium heat. Melt a teaspoon of butter or spray with cooking spray. Once the pan is hot, ladle 1/4 cupfuls of batter onto the pan and cook until bubbles start to form on the top, about 1 to 2 minutes. Flip over and cook another 1 to 2 minutes or until golden brown. Repeat with the remainder of the batter.
To serve: Drizzle with maple syrup or top with peanut butter and syrup!