1. Preheat the oven to 325°F and line an 8-inch square baking pan with parchment paper, leaving overhang on two sides.

2. Stir together the graham cracker crumbs, 3 tablespoons sugar, melted butter, and 1/4 teaspoon salt until evenly moistened.

3. Press the crumb mixture firmly into the bottom of the pan, then bake for 8 to 10 minutes. Let it cool slightly.

4. Beat the softened cream cheese and 2/3 cup sugar until smooth and creamy, scraping down the bowl as needed.

5. Mix in the eggnog, sour cream, flour, vanilla, nutmeg, cinnamon, and pinch of salt until smooth.

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

7. Pour the filling over the crust and smooth the top.

8. Bake for 34 to 40 minutes, until the edges are set and the center still has a slight wobble.

9. Cool at room temperature for 1 hour, then refrigerate for at least 4 hours or overnight.

10. Lift the bars from the pan, slice into squares, and dust with extra nutmeg before serving.