01 - Preheat oven to 400°F and line a baking sheet with parchment paper.
02 - In a large bowl, combine ground beef, ground pork, breadcrumbs, onion, garlic, egg, milk, salt, black pepper, allspice (if using), and chopped parsley. Mix until ingredients are just combined, avoiding overmixing.
03 - Form mixture into 1-inch meatballs and arrange evenly on the prepared baking sheet.
04 - Bake in preheated oven for 15 to 18 minutes, or until browned and cooked through.
05 - In a large saucepan set over medium heat, combine jellied cranberry sauce, chili sauce, brown sugar, apple cider vinegar, Worcestershire sauce, and cayenne pepper (if using). Stir and cook until sauce is smooth and bubbling, about 5 minutes.
06 - Transfer baked meatballs into the saucepan, gently stir to coat, and simmer on low for 7 to 10 minutes to blend flavors.
07 - Serve warm as an appetizer with toothpicks or over rice for a main dish.