Get a clean, large pitcher ready.
Make sure it holds at least six cups.
Chill it in the fridge beforehand.
This keeps everything nice and cold.
Pour the eggnog into your pitcher.
Add the heavy cream on top.
Stir them together until fully mixed.
The cream adds extra richness nicely.
Slowly pour in the Fireball whiskey.
Mix everything together very well.
Stir for about one full minute.
Make sure there are no streaks.
Add the ground nutmeg to mixture.
Stir it in really well.
Add vanilla if you're using it.
Mix one more time thoroughly.
Refrigerate for at least thirty minutes.
Pour into glasses over ice cubes.
Top with fresh whipped cream.
Dust with cinnamon on top.