Preheat oven to 425 degrees F (220 degrees C). In a small bowl, mix together white sugar and cinnamon; set aside.
Place butter in a 9 inch cake pan and heat in the oven until melted. In a blender or food processor, whip eggs and milk. Pour in flour and beat until well combined. Pour batter into hot pan. Sprinkle on sugar and cinnamon.
Bake in preheated oven for 20 to 25 minutes, or until puffed and golden. Dust with confectioners' sugar; serve warm.
