Preheat your oven to 350°F (175°C).
Grease a 9×13 inch baking dish lightly with butter or non-stick cooking spray.
Spread the two cans of apple pie filling evenly across the bottom of the prepared baking dish.
Drizzle the caramel sauce over the apple filling, then sprinkle the ground cinnamon over the top.
Evenly distribute the dry cake mix over the apple and caramel layer. Use a spatula to gently level it out, but do not press the powder down.
Arrange the thin slices of butter across the entire surface of the cake mix, ensuring as much of the dry mix is covered as possible to avoid dry patches.
Sprinkle the optional chopped nuts over the top of the butter slices.
Bake for 40 to 45 minutes, or until the top is golden brown and the fruit filling is bubbling around the edges.
Remove from the oven and allow the dish to cool for at least 10 minutes before serving, which allows the sauce to thicken slightly.