Begin by making the filling.
In a large bowl, cream together the cream cheese and brown sugar until light and fluffy, using a hand mixer.
Add the pumpkin pie spice, pumpkin puree, and vanilla. Beat until well combined, scraping down the sides of the bowl as necessary.
In a trifle dish, lay a bottom layer of cookies evenly. Add ¼ of the pumpkin mixture and spread out into an even layer. Then, add a quarter of the Cool Whip.
Take 6-7 gingerbread cookies and vertically line the outside of the dish with them, sticking the foot-end of the cookie into the bottom pumpkin layer. This will ensure they stand up and are visible from outside the dish.
Next, add ¼ of the pumpkin mixture followed by ¼ of the Cool Whip and spread evenly. Be careful to spread each layer out to the sides of the dish, hugging the cookies. Top with a horizontal layer of cookies and repeat with two more layers (¼ pumpkin mixture, ¼ Cool Whip, then cookies) until all ingredients have been used, ending with a layer of Cool Whip. Place a decorative gingerbread man on top and additional pumpkin pie spice, if desired.
Cover with plastic wrap and stick the trifle dish into the fridge to chill for at least 4 hours to overnight.
Once ready to serve, scoop heaping spoonfuls of cake into bowls. Serve with a drizzle of salted caramel sauce.