Preheat oven to 350°. Combine cake mix, butter and 1/3 cup sweetened condensed milk. Spread into a greased 9 x 13 pan. Bake 8 minutes. Remove from oven, and top with remaining sweetened condensed milk, chocolate and toffee chips, and peanuts. Bake 14-16 minutes. Remove from oven. Top with miniature marshmallows, and drizzle with Caramel packet. Return to oven for 3 minutes until marshmallows are puffed. Cool. Makes 12-15 servings.