In a large mixing bowl, combine softened cream cheese and granulated sugar. Using a hand mixer, beat the mixture on medium speed for about 2-3 minutes until it turns smooth and creamy. Gently fold in half of the Cool Whip until just combined.

Carefully spoon the cream cheese mixture into a pre-made graham cracker crust, smoothing the top to ensure an even layer.

In a separate bowl, whisk together the instant vanilla pudding mix and milk until thickened, about 2 minutes. Fold in the canned pumpkin puree, pumpkin pie spice, nutmeg, and cinnamon until well-blended.

Pour the pumpkin layer over the cream cheese layer in the crust and spread it evenly. Top with the remaining Cool Whip.

Cover with plastic wrap and refrigerate for at least 1 hour to allow the layers to set and meld together.