Pumpkin Cream Cheese Cake

I don't think this one needs any description as the title says it all. :)  It is simply delicious!  Enjoy!
-butter flavored cooking spray
-8 oz cream cheese, at room temperature
-3/4 cup powdered sugar
-2 tsp milk
-1 (29 oz) can pumpkin puree
-1 (12 oz) can evaporated milk
-3 large eggs
-1 1/4 cups sugar
-1 tsp salt
-1 Tbs pumpkin pie spice
-1 (15.25 oz) box yellow cake mix
-2 Tbs cinnamon sugar mixture
-whipped cream, for topping
Preheat oven to 350 F.  Coat a 9x13 pan with the butter flavored cooking spray.  Set aside.
Cream the cheese, powdered sugar and milk.  Set aside.
In a large bowl, combine pumpkin puree, evaporated milk, eggs, salt and spice.  Mix very well.  Add the cake mix and make sure it's well incorporated.  Pour into prepared pan.
Drop dollops of the cream cheese mixture and swirl into the pan. 
Sprinkle on top with the cinnamon sugar.  Coat the cinnamon sugar top with some butter flavored cooking spray.  
Bake in preheated oven for 50-60 minutes or until toothpick comes out clean.
Cool completely, cut into pieces and serve with a dollop of whipped cream, if desired.  Enjoy!