Combine apples and 1/4 cup butter in a medium saucepan, cook over medium heat 5 minutes.
Stir in sugar, cinnamon, and nutmeg, cover and simmer an additional 10 minutes.
Set aside.
Combine flour and salt in a mixing bowl, gradually beat in eggs and milk, mixing well.
Pour 1 tablespoon melted butter in a 10-inch ovenproof skillet.
Add egg mixture to skillet, bake at 450° for 10 minutes.
Watch pancake closely after 5 minutes baking time, as pancake puffs up, immediately puncture it with a fork.
Repeat puncturing as pancake continues to puff up.
Lower temperature to 350°; bake an additional 5 minutes. (Pancake will have lumpy appearance.)
Remove pancake from oven, drizzle with 1 tablespoon butter, and sprinkle with 1 tablespoon powdered sugar.
Spoon apple mixture onto half of pancake, fold other half over apples.
Drizzle top with remaining 1 tablespoon butter, and sprinkle with 1 tablespoon powdered sugar.
Garnish with apple slices sauteed in butter, if desired.