Preheat your oven to 325°F (160°C) and line a 9x13-inch baking pan with parchment paper, leaving an overhang for easy removal.

In a medium bowl, whisk together the graham cracker crumbs, ¼ cup granulated sugar, 1 teaspoon cinnamon, and ½ teaspoon nutmeg.

Pour the ½ cup melted butter into the crumb mixture and stir until well combined and all crumbs are moistened.

Press the crust mixture evenly into the bottom of the prepared baking pan using the back of a spoon or your fingers.

Bake the crust for 8-10 minutes, then remove from the oven and let it cool slightly while you prepare the filling.

In a large mixing bowl, beat the softened cream cheese with an electric mixer on medium speed until smooth and creamy, about 2-3 minutes.

Gradually add ¾ cup granulated sugar to the cream cheese and beat until the mixture is light and fluffy, about 2 more minutes.

Beat in the 2 large eggs and 2 large egg yolks one at a time, mixing until just combined after each addition without overmixing.

Gently fold in the 1 cup eggnog, 1 teaspoon vanilla extract, and ¼ teaspoon freshly grated nutmeg until just incorporated.

Carefully pour the eggnog cheesecake filling evenly over the pre-baked crust in the pan.

Bake for 35-45 minutes, or until the edges are set and the center has a slight jiggle.

Turn off the oven, crack the door open slightly, and let the bars cool in the oven for 30 minutes; then remove and let cool completely at room temperature for about 1 hour.

Transfer the cooled bars to the refrigerator and chill for a minimum of 4 hours, or preferably overnight.

Once thoroughly chilled, use the parchment overhang to lift the bars out of the pan and onto a cutting board.

Use a sharp knife to cut into desired bar sizes, wiping your knife with a warm, damp cloth between slices for clean cuts.

Serve plain or garnish with a dollop of whipped cream and a sprinkle of fresh nutmeg.