In a medium mixing bowl, whisk together the egg yolks and sweetener until the mixture becomes light and creamy, which usually takes about 3 minutes. An electric mixer can make this super easy!
In a saucepan over medium-high heat, combine the heavy cream, almond milk, nutmeg, and salt. Stir continuously until the mixture just begins to simmer. Then, reduce the heat to low.
Now, it's time to temper the egg yolks! Carefully spoon a small amount of the hot almond milk mixture into the egg yolk mixture, whisking vigorously. This slowly raises the temperature of the yolks without scrambling them. Repeat this process, gradually adding all of the hot almond milk mixture to the egg yolks, making sure to keep whisking.
Pour the entire combined mixture back into the saucepan on the stove. Whisk continuously for a few more minutes until it slightly thickens. Don't worry if it's not super thick yet, it will thicken up more as it cools!
Remove the saucepan from the heat and stir in the vanilla extract.
Carefully transfer the eggnog into a pitcher or a container with a lid. Place it in the refrigerator until it's perfectly chilled.
When ready to serve, pour into glasses and top with a sprinkle of ground cinnamon for a festive and healthy treat!