Add the cream cheese, Cool Whip, pumpkin puree, powdered sugar, white chocolate chips, and pumpkin pie spice to a medium mixing bowl.
Mix together with a rubber spatula or hand mixer (on low) until evenly combined.
Transfer to a serving bowl and sprinkle with a little ground cinnamon. Serve immediately or cover and chill in the fridge until ready to serve.
Notes
If you refrigerate the dip before serving, I recommend letting it sit out on the counter for 30 minutes to soften up a bit. The dip will set up to a thicker consistency in the fridge, thanks to the cream cheese.