Beat eggs with electric mixer until light and fluffy. Add flour and milk alternately, beginning and ending with flour; beat well after each addition. Stir in butter and salt.
Heat a well-greased muffin pan in a 450° oven for 3 minutes or until very hot. Spoon batter into muffin pans, filling two-thirds full. Bake at 425° for 20 minutes; reduce heat to 350°, and bake an additional 20 minutes. Serve immediately.