Instructions:
- Preheat oven to 350°F (175°C). Wrap the exterior bottom and sides of a 9-inch springform pan tightly in two layers of heavy-duty foil.
- Combine crushed ginger snaps, sugar, and melted butter. Press firmly and evenly into the bottom of the prepared springform pan. Bake the crust for 10 minutes. Remove and allow to cool while preparing the filling. Reduce oven temperature to 325°F (160°C).
- Beat the softened cream cheese on medium speed until completely smooth. Gradually add the sugar, beating until just combined and creamy. Scrape down the bowl.
- Beat in the vanilla, nutmeg, cinnamon, and salt. Add the eggs one at a time, beating only until just incorporated after each addition. Do not overmix.
- Gently whisk together the eggnog and flour in a separate small bowl until smooth. Slowly pour the eggnog mixture into the cream cheese base, mixing on low speed until just blended.
- Pour the filling over the cooled crust. Place the foil-wrapped springform pan inside a large roasting pan. Carefully pour very hot water into the roasting pan to create a water bath (Bain-Marie), ensuring the water comes about halfway up the sides of the springform pan.
- Bake at 325°F (160°C) for 65–75 minutes, or until the edges are set but the center still has a slight wobble.
- Turn off the oven. Prop the oven door open slightly and allow the cheesecake to cool slowly inside the water bath for 1 hour.
- Remove the pan from the water bath, remove the foil, and let it cool completely on a wire rack to room temperature (about 1 hour). Cover loosely and chill in the refrigerator for at least 4 hours, or preferably overnight.
- Before serving, whip the heavy cream, powdered sugar, and spices until soft peaks form. Dollop or swirl over the chilled cheesecake.