Heat the cream, almond milk, and brown sweetener in a saucepan until steaming but not boiling.
Whisk the egg yolks in a bowl. Slowly pour in a small amount of the warm cream while whisking constantly.
Return the tempered yolk mixture to the saucepan and cook over low heat until it lightly coats a spoon.
Remove from the heat and stir in the butter, vanilla, salt, and xanthan gum if using.
Strain the mixture, cool it, and refrigerate for at least 4 hours. Churn according to the ice cream maker instructions.
Transfer to a covered container and freeze for 2 to 3 hours before serving.
