1Preheat oven to 350 degrees F (175 degrees C). Lightly grease a 9x13 baking dish.
2Combine the cake mix, vanilla pudding mix, pumpkin, water, oil, eggs, and pie spice in a large mixing bowl; pour into the prepared dish.
3Bake in the preheated oven for 45 to 50 minutes. Allow to cool to room temperature on a wire rack. Cut the cake into 1-inch cubes.
4Whisk together the milk and cheesecake pudding mix. Allow to set, about 2 minutes. Fold the whipped topping into the pudding mixture.
5Layer 1/3 of the cake cubes into the bottom of a large bowl; top with 1/3 of the cream mixture and sprinkle with 1/3 of the pecans and toffee bit. Repeat layering until all ingredients are uses. Refrigerate 1 hour before serving.
1 (18.25 ounce) package spice cake mix
1 (3.4 ounce) package instant vanilla pudding
1 cup pumpkin puree
1/2 cup water
1/2 cup vegetable oil
2 teaspoons pumpkin pie spice
2 cups cold milk
2 (3.4 ounce) packages cheesecake flavor instant pudding and pie filling