Add egg yolks and sugar into a large bowl and mix until well blended.
6 large egg yolks, 1 cup Sugar
Add milk, cinnamon, nutmeg, and vanilla extract into a small saucepan. Then, bring all to a low boil on medium heat while stirring.
2 cups Milk, ½ tsp Cinnamon, ½ tsp Nutmeg, ½ tsp Vanilla extract
Slowly add the mixture to the bowl with sugar and add yolk. Ensure to combine everything is thoroughly before continuing with the next step.
Return the content of your bowl to your saucepan and heat it up to 160°F while stirring, use a thermometer for easy measuring. Then, remove the pot from the heat.
Whisk in the heavy cream and your choice of rum, bourbon, or brandy while the mix is cooling.
1 cup Heavy cream, 1 cup Liquor
Strain the finished eggnog with the help of a fine-mesh strainer and store it in the fridge to chill before serving.
When it's time to serve your eggnog, you can garnish it with spices like ground cinnamon, nutmeg, or a cinnamon stick.