Caramel Apple Upside-Down Cake

1 cup (2 sticks) butter, divided
1 cup firmly packed light brown sugar
1 large Granny Smith apple, cored and thinly sliced
1 (15.25-ounce) box butter (or yellow) flavored cake mix
3 large eggs
1 cup water

Preheat the oven to 325° F. Add 1/2 cup (1 stick) of the butter and the brown sugar to a
well-seasoned, medium (about 10.25") cast-iron skillet. Place the skillet over medium heat,
and stir until the butter is melted and the mixture is combined. Remove from the heat.

Melt the remaining 1/2 cup (1 stick) butter in a small bowl in the microwave. In a large
bowl combine the cake mix, eggs, melted butter and 1 cup water. Mix well.

Place the sliced apples in the skillet on top of the caramel mixture arranging them in
whatever fashion you like. Pour the cake batter on top of the apples. Bake 45 to 50
minutes or until a toothpick inserted in the center comes out clean. Immediately cover
the skillet with a platter and invert to remove the cake.