Preheat the oven to 350°F or 175°C. Grease a 9 x 13-inch baking dish, paying attention to the corners where the caramel can stick.
Spoon both cans of apple pie filling into the dish and spread them evenly. Sprinkle cinnamon over the fruit and drizzle the caramel sauce across the surface.
Pour the dry cake mix directly over the apples. Use the back of a spoon to spread it into a level layer, but do not stir it into the filling.
Arrange the thin butter slices over the cake mix, covering as much of the dry surface as possible. Small uncovered areas are fine because the butter will melt outward.
Sprinkle chopped pecans over the top when using them. Bake for 42 to 47 minutes, until the top is browned and the filling bubbles around the sides.
Rest the cake for 10 to 15 minutes before serving. Spoon it into bowls while warm and add ice cream or extra caramel sauce if desired.
