Bring heavy cream, allulose, cocoa powder, xanthan gum, and sea salt to a simmer over medium-high heat. Cook, whisking constantly, until the sweetener is dissolved.
Remove from heat and stir in chocolate, MCT oil, and vanilla extract.
Chill thoroughly in the refrigerator and process according to the ice cream makers manufacturers instructions.
It will initially be like soft-serve. If you prefer it firmer, place it in a freezer-safe dish and cover. Freeze for 2 hours.
Notes
As long as you have it in a sealed container, this ice cream will store for up to three months in the coldest part of your freezer. (Assuming you don’t have kids that stand staring into the freezer for hours as if a meal is going to appear suddenly.)