Heat oven to 350°F.
In a 1-quart heavy saucepan, cook butter, whipping cream, and brown sugar over low heat, stirring occasionally, just until the butter is melted. Pour into a 13x9-inch pan. Sprinkle with pecans; top with sliced apples.
In a large bowl, beat cake mix, water, oil, eggs, and apple pie spice with an electric mixer on low speed until moistened, then on medium speed 2 minutes, scraping the bowl occasionally. Carefully spoon the batter over the apple mixture.
Bake 41 to 47 minutes or until a toothpick inserted near the center comes out clean. Cool in the pan 10 minutes. Loosen the sides of the cake from the pan. Place a heatproof serving platter upside down on top of the pan; carefully turn the platter and the pan over. Let the pan remain over the cake for about 1 minute so e caramel can drizzle over the cake. Remove the pan.
In a small bowl, mix frosting and whipped topping.
Serve the warm cake topped with the frosting mixture and drizzled with caramel topping. Store covered in the refrigerator.
