Place butter in a 10-inch pieplate; bake at 425° until butter melts. Remove from oven, and set aside.
Combine flour, milk, eggs, and nutmeg in a medium mixing bowl; stir until well blended. Pour flour mixture into butter (do not stir). Bake at 425° for 15 minutes; remove from oven, and sprinkle with powdered sugar. Bake an additional 5 minutes. Cool slightly; cut into wedges. Serve with Red Plum Jelly.