Combine the eggs and sugar in a bowl and whisk until thoroughly combined
Pour the whole milk into a saucepan and stir in the ground cinnamon and ground nutmeg and a pinch of salt
Whisk the egg mixture into the milk mixture
Heat the mixture over medium heat while stirring constantly. Stirring constantly is very important to prevent the milk from scorching or scrambling the eggs.
While the mixture cooks add in the candy thermometer and when the mixture reaches 165° on the candy thermometer remove from the heat and slowly whisk in the heavy whipping cream and vanilla extract
Cool slightly before tasting and add more sugar or spices as desired
Allow the mixture to cool completely
Once cooled placed in a covered container and refrigerate overnight or until thoroughly chilled
When you are ready to serve you can either pour the mixture into cups as is or you can place in a blender or vita-mix to make it frothy, an immersion blender can work as well
Whip one cup of heavy whipping cream to make fresh whipped cream for the topping
If serving in a punch bowl you can fold the fresh whipped cream into the mixture for a traditional look or you can keep it separate and simply use it as a topping for the eggnog (using it just as a topping is my preference)
Top each cup with fresh nutmeg and fresh orange zest