Clean cast-iron skillet with soap and water. To prevent rusting, place in a warm oven or on stove top over medium heat till water evaporates.

Melt 3 tablespoons butter in a 10-inch cast-iron skillet. Remove from heat, and sprinkle with brown sugar and ginger.

Toss apple slices with lemon juice, and arrange over brown sugar mixture; set aside.

Beat 1/2 cup softened butter at medium speed with an electric mixer until creamy; gradually add sugar, beating well. Add eggs, 1 at a time, mixing after each addition.

Combine flour and next 3 ingredients; add to butter mixture alternately with milk, beginning and ending with flour mixture. Stir in vanilla. Spoon evenly over apples.

Bake at 350° for 35 to 40 minutes or until a wooden pick inserted in center comes out clean. Cool in skillet on a wire rack 5 minutes; invert onto serving plate. Makes 1 (10-inch) cake.