Preheat the oven to 325°F (165°C). Grease the bottom of a 9-inch springform pan.
In a mixing bowl, combine graham cracker crumbs, melted butter, and sugar until evenly mixed. Press this mixture firmly into the bottom of the prepared springform pan to create the crust.
In a large mixing bowl, beat the softened cream cheese with an electric mixer on medium speed until smooth and creamy.
Gradually add the sugar and continue to mix until well combined.
Add the eggnog, eggs, vanilla extract, nutmeg, cinnamon, and salt to the cream cheese mixture. Mix on low speed until all ingredients are fully incorporated, scraping down the sides as needed.
Pour the cheesecake filling over the prepared crust in the springform pan. Smooth the top with a rubber spatula.
Bake in the preheated oven for about 60 minutes, or until the center is set but slightly jiggly.
Once done, turn off the oven and crack the door open. Let the cheesecake cool in the oven for an hour to prevent cracking.
Remove the cheesecake from the oven and allow it to cool to room temperature. Once cooled, refrigerate for at least 4 hours, preferably overnight.
Before serving, top with whipped cream and sprinkle with ground nutmeg if desired.