In a large mixing bowl, mix room temperature cream cheese and sugar until smooth and no cream cheese lumps remain.
Mix in eggs, one at a time until blended.
Mix in sour cream and vanilla until blended.
Pour 1/2 of the cheesecake mixture over the shortbread base and spread evenly.
The remaining cheesecake mixture, add pumpkin, cinnamon, nutmeg, and ground ginger, mix until fully blended.
Gently drop spoonfuls of pumpkin cheesecake mixture over the cheesecake layer in the pan, spread evenly.
Bake at 325 F for 45-50 minutes until the centre is slightly jiggly.
Cool for 1 hour and refrigerate for at least 4 hours before cutting into squares. Best to let it set overnight in the refrigerator.