In a blender, process flour, milk, salt, egg and melted butter until smooth. Refrigerate batter for 30 minutes.
Heat a flat pan with cooking spray over medium-low heat. Pour in batter and swirl to create a thin layer. Cook for 1 minute and flip. Cook for another 30 to 60 seconds. Repeat until all of the batter is used.
Make the bananas by heating butter over low heat in a large pan. Add the brown sugar, vanilla extract and cinnamon. Stir until the sugar is dissolved. Add bananas and gently stir to coat with sauce. Cook for 2 to 3 minutes.
Assemble crepes with bananas and serve with ice cream and more cinnamon.