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