In a medium mixing bowl beat eggs with a wire whisk until frothy. Add flour, milk, 1 tablespoon of the melted margarine or butter, and salt; beat until smooth.
Heat an 8-inch round baking pan or ovenproof skillet in a 450 degree F oven for 2 minutes. Add remaining 1 tablespoon melted margarine; swirl to coat pan. Pour batter into hot pan. Bake pancake in the 450 degree F oven for 18 to 20 minutes or until puffed and golden.
Meanwhile, for filling, in a medium skillet melt the 2 tablespoons margarine or butter over medium heat. Stir in brown sugar until combined. Stir in apple slices, cinnamon, and nutmeg. Cook, uncovered, for 3 to 5 minutes or until apples are crisp-tender, stirring occasionally.
To serve, remove pancake from oven. Spoon some of the filling into center of pancake. Sprinkle with powdered sugar. Cut into wedges. Pass the remaining filling. Pancake will collapse as it cools. Makes 6 servings.