Prepare apple pie filling and allow to cool completely. Refrigerate if necessary.
In a medium-sized bowl, combine vanilla pudding with cinnamon and apple pie spice. Whisk together. Add milk and whisk until pudding mix is dissolved. Refrigerate 10-15 minutes until firm.
Put your mixing bowl and wire whisk in the freezer to help it get very cold. This is optional, but something I usually do.
Beat heavy whipping cream on medium-high speed. As whipped cream begins to thicker, slowly added powdered sugar and apple pie spice increasing speed to high and beat until still peaks form. Divide whipped cream in half and set whipped cream in the refrigerator.
Best the cream cheese on medium-high speed for 2-3 minutes, scraping down the bowl occasionally. Slowly add the pudding to the cream cheese, and beat together to eliminate any lumps in the cream cheese. Scrape the bowl occasionally.
Combine half of the whipped cream in the pudding mixer and fold until combined.
To build the tiramisu, layer the bottom of a 9x9x2 inch pan with parchment paper. In a shallow bowl, combine milk and bourbon and mix together. Dip each lady finger in the liquid and align them on the bottom of the pan. Drizzle with caramel sauce Cut to fit if necessary.
Layer half the mousse on top of the lady fingers and spread evenly. Add 1 ¼ cups of apple pie filling and spread across the mousse, gently pressing it in.
Repeat the above steps, dipping lady fingers in liquid to create the third layer and drizzle with caramel. Spread remaining mousse and apple pie filling. Top the tiramisu with remaining whipped cream. Right before serving, drizzle with remaining caramel and sprinkle with walnuts or toffee.