Preheat oven to 350° F.
Melt 1/2 cup butter in cast iron skillet by placing in oven. Remove skillet and add brown sugar, stir and return to oven.
Take the skillet out of oven and place one refrigerated pie crust on top of the brown sugar. Place 1/2 the sliced apples on top of the crust. Add 1/2 cup sugar and 1 teaspoon of cinnamon. Place another pie crust on top of that, pour in the remaining apples and sprinkle again with 1/2 cup sugar and 1 teaspoon of cinnamon. Top it off with the third pie crust. Add to the top 1/4 cup sugar and 1 tablespoon of butter. Cut 4 slits in the top crust for steam to escape.
Place in oven and bake for 45 minutes until the crust is golden brown. Serve warm with vanilla ice cream if desired.
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.