Preheat your oven to 350°F (175°C).
Place the pre-made pie crust in the 9-inch pie pan and crimp the edges as desired.
To prevent the crust from puffing up, line the crust with baking paper and fill it with pie weights or dried beans.
Bake the crust in the preheated oven for 10 minutes. After 10 minutes, remove the weights and paper and bake for an additional 5 minutes until lightly golden. Set aside to cool slightly.
In a mixing bowl, whisk the eggs until lightly frothy.
Add the eggnog, granulated sugar, brown sugar, heavy cream, cornstarch, vanilla extract, nutmeg, cinnamon, and salt to the bowl. Mix well until the ingredients are fully combined and smooth.
Pour the eggnog mixture into the pre-baked pie crust.
Bake the pie in the oven for 30 minutes, or until the filling is set but still slightly jiggly in the center.
Remove the pie from the oven and allow it to cool at room temperature for at least 30 minutes before refrigerating for an additional hour.
Serve chilled, topped with whipped cream if desired.