Prepare a 9x13 inch casserole dish by spraying it with cooking spray and preheating the oven to 350°F.
In a mixing bowl, mix the dark brown sugar and cinnamon together until well blended.
Cut each cinnamon roll into fourths using a pizza cutter.
Place the cinnamon roll pieces into the sugar and cinnamon mixture, and gently toss until all the pieces are coated.
Transfer the mixture into the casserole dish, and spread it out evenly.
Pour the melted butter over the mixture, making sure to focus on the edges to prevent them from drying out.
In another mixing bowl, combine the apple pie filling and caramel syrup.
Cut the apple slices into bite-sized pieces.
Spread the apple pie mixture on top of the cinnamon roll mixture, making sure it is evenly distributed.
Bake for 35-40 minutes, or until the cinnamon rolls are firm to the touch and turning golden brown.
After removing from the oven, allow to cool for 10 minutes, then drizzle with the icing from the cinnamon rolls and extra caramel syrup (optional).
Serve the dish while it is warm.
