Add the heavy cream, apple cider vinegar, prepared horseradish, spicy brown mustard, Worcestershire sauce, lemon juice, black pepper, salt, cayenne pepper, and garlic powder.
Shake or whisk vigorously until well mixed. The consistency should be creamy and smooth, with a rich flavor profile from the tangy vinegar and the heat of the cayenne and black pepper.
Store the sauce in an airtight container or the mason jar in the refrigerator.