Mix egg yolks and 1/2 off the sugar in a saucepan (no heat) until combined.

Slowly warm over LOW HEAT until slightly thickened, whisk in rum and vanilla. (personally I love a coffee liquor more than rum, but I don't think that's technically a true eggnog anymore...) If you decide to forego the liquor, simply add more orange juice instead and use an extra teaspoon or two of vanilla.

Slowly whisk in milk and orange juice.

Before the mixture gets too warm (around 80 degrees or so) you’ll need to temper in the egg white. What this means is that you take a spoon full of warm milk mixture and whisk into the egg whites before pouring the egg whites into the pan. This ensures that the eggs don’t ‘cook’ the moment they touch the warm milk. Chunky eggs in a drink are no good. Believe me – I’ve had it happen.{{shudder}} Once the egg white has been mixed with a spoonful of milk mixture, pour it into the pan while stirring constantly.

Once the egg is fully incorporated, gently fold in the whipped cream.

Heat to the temperature you desire, though keeping it under 110-120 will have the best texture.

This drink can be made ahead of time and kept warm in a crockpot on low (if your slow cooker has a warm setting!) or placed in the refrigerator for a few hours until needed. Leftovers can be kept in the fridge (the heated version may keep longer than the unheated version) and you can even use it to make your french toast with it the next morning!