Tightly wrap a 9-inch springform pan in heavy-duty foil to prevent leaks from the water bath.
Lightly spray the pan with nonstick cooking spray and set aside.
Bake the crust. In a medium bowl, stir together crushed graham crackers, ground ginger, and melted butter with a fork until thoroughly combined and clumps start to form.
Use your fingers to evenly press the crumbs into the bottom and about 1 inch up the sides of the pan.
Bake the crust in the oven for 8 minutes. Remove the pan from the oven and set aside to completely cool.
Bake your sweet potatoes. Increase the oven temperature to 400℉.
Line your baking sheet with aluminum foil and place four sweet potatoes on the baking pan. Pierce each sweet potato several times with a fork.
Bake for about 50 minutes, until tender. Remove from the oven and let them cool completely. Then, peel the skin off with your fingers and puree the sweet potatoes in a food processor or blender.
Make the sweet potato cheesecake filling. Preheat the oven to 350℉.
Beat the cream cheese, in a stand mixer, until smooth. Add the sugar and mix until combined. Add one egg at a time, letting each egg completely mix before adding the next. Add allspice, vanilla, heavy cream, and sweet potato puree and mix until you have a smooth and creamy consistency.
Make a water bath. Pour the batter into the prebaked crust. Place the springform pan into a larger baking pan. Pour boiling water into the larger pan until it is halfway up the side of the cheesecake pan.
Bake for 55-60 minutes. When the edge looks like it's set but the center is still jiggly, turn the oven off and leave the door cracked. Let your cheesecake rest for one hour.
Carefully (it's still hot!) remove the cheesecake from the water bath and place it on a cooling rack to cool completely.
When the sweet potato cheesecake is completely cooled, place it in the fridge overnight, or for eight hours.
Top with whipped cream, nuts, and caramel sauce, and serve!