Put the milk and cream in a blender, then start blending on low.

Heat the peanut butter very briefly, if needed, to become soft enough to blend. Do not let it get hot. Drizzle into the blender with the swirling milk/cream mixture (so it combines rather than clumps up). Turn off the blender when well combined.

In a small bowl, combine the nonfat dry milk, sugar or sweetener, salt and guar gum if using. Stir together and break up any lumps.

Turn the blender on low again, then slowly add the dry ingredient mixture until well blended. Taste and add additional salt and stevia if needed.

Pour mixture into ice cream freezer, then process according to manufacturer directions.

If adding a fudge ribbon, one option is to drizzle into the machine at the VERY end (to keep it separate). Otherwise drizzle over the ice cream as you transfer it to the freezer container. (I alternate scooping in ice cream and drizzling--don't be a perfectionist).