Make the crepe batter: Blend banana in a food processor until totally smooth. Add melted butter, blend again. Add remaining ingredients and blend until they are combined. Transfer batter, which will look pretty thin, to a bowl (even easier later if it has a spout), cover with plastic wrap and chill for at least an hour, preferably overnight, and up to two days. When you remove the batter, it will seem surprisingly thick. Stir it to redistribute the ingredients before using it.
Cook the crepes: Heat a medium skillet or crepe pan over medium-high heat. Once heated, brush pan thinly with melted butter. Pour 1/4 cup batter into skillet, swirling it until it evenly coats the bottom and cook, undisturbed, until the bottom is golden and the top is set, about 2 to 3 minutes. Flip* the crepe and cook it for 30 seconds on the other side, before transferring it to a plate to cool. Repeat with remaining batter. You can stack your crepes and they should not stick together. Let crepes cool completely.
Original recipe: http://smittenkitchen.com/2012/04/banana-bread-crepe-cake-with-butterscotch/