Place butter in a 10-inch ovenproof skillet. Place in a 400º oven for 3-5 minutes or till butter melts. In a bowl, beat eggs with a rotary beater till combined. Add flour, milk, and salt. Beat till smooth. Immediately pour into the hot skillet. Bake about 18 minutes or till puffed and well-browned. Serve with maple syrup and/or fruit and sprinkle with powdered sugar.