Prepare the Oven and Baking Pan: Preheat the oven to 350°F (175°C). Coat a 9 × 13-inch baking pan with nonstick cooking spray to prepare it for the cake batter.
Mix the Cake Batter: In a large mixing bowl, combine the vanilla cake mix, apple pie spice, water, vegetable oil, eggs, and vanilla extract. Using an electric mixer on medium speed, beat the ingredients for 2 minutes until the batter is thoroughly combined.
Fold in the Apple Filling: Add the coarsely chopped apple pie filling to the batter. Gently fold it in with a rubber spatula until the apples are distributed throughout the mixture.
Fill the Baking Pan: Pour the prepared batter into the greased 9 × 13-inch pan. Use the spatula to spread it evenly across the pan.
Bake the Cake: Place the pan in the preheated oven and bake for 28–33 minutes, or until the cake is baked through.
Cool the Cake Briefly: Remove the pan from the oven and place it on a wire cooling rack. Allow the cake to cool for 10 minutes while it remains in the pan.
Poke Holes in the Cake: While the cake is still warm, use a straw to poke holes approximately 1 inch apart across the surface. Push the straw about halfway into the cake to create openings for the caramel sauce.
Add the First Caramel Layer: Measure out ¾ cup of the caramel sauce. Drizzle it evenly over the warm cake, allowing the sauce to seep into the holes. Leave the cake to cool completely before adding the topping.
Spread the Whipped Topping: Once the cake has cooled completely, spread the thawed whipped topping evenly over the surface.
Finish with Caramel and Toffee: Sprinkle the toffee bits over the whipped topping. Drizzle the remaining ¼ cup of caramel sauce over the top to finish the cake.
Store the Leftovers: Cover any leftover cake and refrigerate for up to 3 days.
