In a mixing bowl, combine the sugar, xanthan gum and salt and stir well. Add the milk, then whisk vigorously for at least a minute or until you can feel the mixture thickening slightly.
Add the yogurt, cocoa powder, syrup and vanilla and whisk for another minute until smooth. The cocoa may make it a little lumpy, but it will smooth out in the freezer. Just do your best to get it mixed in. Whisk in the vodka if using.
Churn in your ice cream maker using manufacturer directions, then transfer to containers.
You can serve this right away as soft serve yogurt or freeze and scoop.
This makes about 25 oz (weight) of ice cream, so a little over 3 cups or 6 (½ cup) servings.
Notes
The calorie count is approximate. Definitely put it in your own calculator if you are seriously watching macros. I used allulose (0), whole milk (170), yogurt (230), cocoa powder (90), maple syrup (130) and vodka (28)