Preheat the oven to 420°F. In a medium size bowl, mix together the flour, baking powder, baking soda, salt, white sugar, egg and milk until well blended. Set aside.
Using the cast-iron skillet melt the butter. Add the apples and sprinkle on the cinnamon, brown sugar and nutmeg. Cook the apples for 4 to 5 minutes until tender.
Once tender pour the pancake batter over the apples and place the entire cast iron skillet in the oven and cook for 10 to 12 minutes until the top of the pancake has browned slightly.
Remove the cast iron skillet from the oven.
Be aware the cast-iron skillet will be very hot. Sprinkle the top of the Apple pancake with powdered sugar and slice the pancake into pie-sized servings and serve apple side up with maple syrup.