Preheat the oven to 325°F (160°C).

Prepare the crust: In a bowl, combine graham cracker crumbs and melted butter until well mixed. Press the mixture into the bottom of a springform pan.

Bake the crust in the preheated oven for 10 minutes, then remove and allow it to cool.

In a mixing bowl, beat the softened cream cheese until smooth. Gradually add the sugar, mixing well until fully combined.

Add in the eggnog, vanilla extract, ground nutmeg, ground cinnamon, and flour. Mix until all ingredients are incorporated and smooth.

Add the eggs one at a time, mixing on low speed after each addition until just combined.

Pour the filling over the cooled crust and smooth the top with a spatula.

Bake for 50-60 minutes or until the edges are set and the center has a slight jiggle.

Turn off the oven and crack the oven door, allowing the cheesecake to cool gradually for 1 hour.

After cooling, refrigerate the cheesecake for at least 4 hours or overnight before serving.

Before serving, top with whipped cream and a sprinkle of freshly grated nutmeg if desired.