Heat the oven to 325°F (163°C), allowing it to reach the proper temperature while the cheesecake filling is prepared.
Place the cream cheese, white sugar, and vanilla extract in a large mixing bowl. Beat until the ingredients form a smooth, evenly blended mixture.
Add the eggs individually, beating after each addition until the cheesecake batter is thoroughly combined and smooth.
Measure out 1 1/3 cups of the prepared cheesecake mixture. Spread this portion evenly across the bottom of the 9-inch graham cracker crust, then set the crust aside.
Add the pumpkin puree and pumpkin spice blend to the cheesecake batter remaining in the bowl. Whisk gently until the pumpkin is completely incorporated and the mixture has a uniform consistency.
Carefully spoon the pumpkin cheesecake mixture over the plain cheesecake layer. Use a spatula to distribute it evenly without disturbing the layer underneath.
Transfer the assembled cheesecake to the preheated oven. Bake for 35 to 40 minutes, until the center is nearly set while retaining a slight jiggle.
Remove the cheesecake from the oven and leave it at room temperature for approximately 1 hour to cool.
Once cooled, refrigerate the cheesecake for at least 3 hours. For a fully developed texture, it may instead be refrigerated overnight.
Serve the pumpkin pie cheesecake chilled. If desired, finish individual slices with whipped cream before serving.