Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper or aluminum foil. Lightly spray with cooking spray.
In a large bowl, combine all meatball ingredients (ground beef, ground pork, breadcrumbs, minced onion, garlic, egg, Worcestershire sauce, and seasonings). Mix gently with your hands until just combined – overmixing will make tough meatballs!
Form the mixture into 1-inch balls, using about 1 tablespoon of mixture per meatball. Place them evenly spaced on the prepared baking sheet.
Bake the meatballs for 15-20 minutes until browned and cooked through (internal temperature should reach 165°F/74°C).
While meatballs are baking, prepare the sauce. In a medium saucepan, combine cranberry sauce, orange juice, brown sugar, apple cider vinegar, soy sauce, garlic powder, cinnamon, and cloves.
Bring the sauce mixture to a simmer over medium heat, stirring occasionally, until sugar is dissolved and ingredients are well combined.
Slowly stir in the cornstarch mixture and continue to simmer, stirring frequently until the sauce thickens, about 3-5 minutes.
Transfer the cooked meatballs to the saucepan with the cranberry sauce (or to a slow cooker if serving later) and gently toss to coat.
Let the meatballs simmer in the sauce for 5-10 minutes to absorb the flavors. If using a slow cooker, keep on the warm setting for up to 2 hours.
Transfer to a serving dish, garnish with fresh rosemary sprigs if desired, and serve warm with toothpicks or small forks.