Prepare sous vide water bath by filling a deep pot with water and heating it, aiming for a temperature of 80 degrees C. In a different pot, heat the heavy cream to a simmer. Whisk in the chocolate, erythritol, vanilla extract, and salt. Remove from heat.
Whisk in the egg yolks one at a time until the mixture is smooth and glossy.
Divide into sealable containers or mason jars and secure the lids tightly.
Place sealed jars at the bottom of the water bath, and cook the chocolate cream pots for 60 minutes.
Remove jars from the water bath, let them reach room temperature, then place in the fridge to cool for a minimum of 3 hours. Serve cold, optionally with whipped cream and ground nutmeg and/or cinnamon.
Serving Size 1 glass