Preheat oven to 350 degrees. Spread butter over the bottom and sides of the iron skillet. Sprinkle the brown sugar over the bottom of the skillet.Lay the pear slices in one layer over the brown sugar.
Prepare the gingerbread mix according to package directions.Pour batter into the prepared pan. Bake for 35 to 40 minutes or until a toothpick inserted in the center comes out clean. Cool in skillet for 5 minutes. Run a sharp knife along the sides of the pan. Place a serving plate, upside down, over the top of the pan and invert the cake onto the plate.