Start with a clean 32-ounce mason jar. Add the cannabis milk, sugar, and salt. Cover and gently shake until sugar is dissolved.
Add the heavy cream and vanilla to the jar. Cover and gently shake to incorporate.
Place the jar in the refrigerator for at least 2 hours; overnight is fine.
Set up your ice cream maker per operating instructions. If you are using a unit with a removable freezer bowl, make sure it has been frozen for at least 24 hours in advance.
Pour the milk mixture into an already running ice cream machine (or according to your machines specific directions.) Mix until thickened, about 15-20 minutes. It should resemble a loose soft-serve consistency.
Transfer ice cream to a 1 1/2 quart, airtight, freezer container.
Place in the freezer for at least 2 hours to firm up before enjoying.
Ensure the freezer bowl has been frozen for at least 24 hours if your ice cream maker requires it.
You can substitute lower fat cream such as half-and-half for the heavy cream and lower-fat milk for the whole milk, but this can affect consistency and mouthfeel. The higher fat content will produce a richer and creamier end product. If substituting, use equal volumes for the substituted ingredient.