Mix flour and brown sugar together, use fingers to break up any lumps of sugar. In a separate container, mix one egg with milk and melted butter. Combine with dry ingredients and then add in the mashed banana and mix again to combine. Do not overmix. Let batter sit for 5 minutes. In the meantime, heat a non-stick skillet and brush with either vegetable oil or melted butter. Drop batter into the pan (I like to use a small ladle to keep the size uniform)--cook until bubbles begin to form on top, flip and cook until golden brown. Serve with butter, maple syrup, sour cream or whatever you like on top.