Preheat the oven to 400°F and line a large baking sheet with parchment paper.
Add the ground turkey, stuffing mix, eggs, milk, onion, and seasonings to a large bowl. Mix just until everything is evenly combined.
Roll the turkey mixture into about 24 meatballs and arrange them on the prepared baking sheet, leaving a little space between each one. Bake for 25-30 minutes, or until cooked through and the centers reach 165°F.
While the meatballs are baking, add the cranberry sauce, barbecue sauce, brown sugar, Dijon mustard, and apple cider vinegar to a large skillet. Stir over medium-low heat until the ingredients are well combined and the glaze is smooth and slightly thickened.
Spoon the meatballs over mashed potatoes and drizzle with the warm cranberry glaze. For an appetizer, add the cooked meatballs directly to the skillet and gently toss until evenly coated.