Preheat and prepare the pan.
Preheat the oven to 350 degrees. Line a 13x9 baking pan (straight sided pan is preferable) with parchment paper, leaving the paper to overhang the sides. Lightly spray parchment with cooking spray. Set aside.
Make the crust and topping.
In a medium bowl combine the dry cake mix, cinnamon, melted butter, and apple cider with a fork until well incorporated and a soft dough forms. Divide the dough in half and press one half into the bottom of the prepared baking pan.
Bake the crust for 10 minutes and then remove from oven. Carefully spread the caramel dip in an even layer on top of the parbaked crust. Sprinkle on chopped nuts, diced apples, and white chocolate chips. Use your fingers to drop small bits of the remaining cake mixture dough on top.
Bake the dessert for 20-25 minutes or until topping just barely begins to brown. Tent with foil if white chocolate begins to brown too quickly. Let cool.
Make the drizzle.
Combine the powdered sugar and water in a small bowl and mix well with a spoon. Drizzle over the top of the bars and let it set up. When ready to serve, use parchment paper to remove from pan. Slice into small squares. Makes 24+ squares.
Notes: I kept these refrigerated and found it easier (cleaner) to cut them when they were cold.
Adapted from Inside BruCrew Life