In a mixing bowl, put your 2 cups of heavy cream and 1 cup of coconut milk.
In separate containers, separate 3 eggs into whites and yolks.
Whip your egg whites until peaks form.
Whisk your egg yolks until they are creamy.
Add your egg yolks to the coconut milk and heavy cream, whisking it in so that it's mixed well.
Mix the egg whites into the cream/coconut milk well.
Add your vanilla to the mixture.
Add your spices to the mixture, this is where you can add your sweetener to taste.
Mix the ingredients well together, ensuring that there are no lumps in the mixture.
In a container, whisk an egg together until it is consistent throughout (no whites showing). Mix it into your eggnog.
Now the rum! Measure out however much you want, of course - the more the better! Pour it into your egg nog and mix well.
Enjoy! Adjust your sweeteners/spices if need be, I usually add a little bit more because I like the flavor punch.