Chill a highball glass, martini glass, or a mug by placing it in the freezer or fridge for a few minutes – alternatively, you can also just fill it with ice.
When it’s chilled, pour 2 oz of your chosen spirit (brandy, bourbon, or dark rum) and vanilla extract, and 4-6 oz of eggnog into it – the amount will depend on how strong or sweet you want your cocktail to be.
Stir your mixture gently to mix the eggnog and alcohol thoroughly or you’ll end up with patches of alcohol or eggnog.
When mixed, sprinkle a dash of ground nutmeg over the top of your glass – alternatively, you can also add a dash of ground cinnamon or mix those two to give it that extra holiday flavor.
Optionally, top off with a dollop of whipped cream or garnish with cinnamon sticks for a more aromatic experience.