In a blender, combine all the ingredients and blend until well combined. Place the crepe batter in the refrigerator for 20 minutes.
In a heavy small non stick skillet or crepe pan, lightly brush the pan with melted butter and heat over medium-high heat. Pour in about 3 tablespoons of batter and tilt the pan to coat.
Cook for 1 or 2 minutes and then flip with a thin metal spatula to finish cooking the other side, another minute.
Repeat with remaining batter. Keep the crepes warm while preparing the rest of the crepes.
To assemble: Spread some arequipe filling in the center of each crepe and fold or roll.