Preheat the oven to 350°F. Spray a non-stick 13x9-inch metal baking pan with baking spray. Set aside.
Using an electric mixer, beat together the cake mix, water, eggs and oil as directed on the package adding 1 tsp apple pie spice or ground cinnamon. Decrease the water called for on the box by 1/4 cup. Beat until smooth and fully moistened.
By hand mix in 1 can of apple pie filling. Spread cake batter into the prepared pan.
Bake for 30-40 minutes or until a toothpick inserted into the center comes back clean.
Meanwhile, using an electric mixer, beat together the pudding mix (both boxes) and 3 cups whole milk. Beat until thickened, but still pourable.
Remove the cake from the oven and immediately poke holes over the entire cake using the handle of a wooden spoon or similar. Be generous.
Spread 1/2 of the caramel pudding into the holes. Mix the remaining pudding with the final can of apple pie filling by hand. Spread over the pudding layer.
Cover with plastic wrap and chill for 4 hours or overnight.
Frost the top with whipped topping and sprinkle with cinnamon and toffee bits just before serving.