01 - Combine almond milk and heavy cream in a medium saucepan over medium heat. Warm gently until steaming, being careful not to boil the mixture.
02 - Whisk eggs and powdered erythritol in a mixing bowl until the mixture becomes pale and smooth, approximately 2 minutes.
03 - Slowly ladle the warm milk mixture into the eggs while whisking continuously. This gradual process prevents curdling and creates a smooth base.
04 - Return the mixture to the saucepan and cook over low heat, stirring constantly with a whisk or wooden spoon. Continue for 5 to 8 minutes until the mixture slightly thickens and coats the back of a spoon.
05 - Remove from heat immediately. Stir in ground nutmeg, ground cinnamon, and vanilla extract until fully incorporated. Add rum or bourbon now if using alcohol.
06 - Transfer the eggnog to a bowl or pitcher. Refrigerate for at least 1 hour, though longer chilling improves flavor and texture.
07 - Pour chilled eggnog into serving glasses. Top with freshly whipped cream and dust with additional nutmeg or cinnamon before serving.