Rinse and wash cranberries under running water. Discard soft and bruised berries. Set aside to drain.
In a small saucepan, add cranberries. Add dark brown sugar, orange zest, orange juice and beef broth. Cook over medium-low heat until all the cranberries are soften and burst, about 15 minutes.
Strain through a sieve into a medium bowl. Discard skins and seeds. Return the sauce back to the saucepan. Add dijon mustard, Worcestershire sauce, and rosemary sprig. Season with salt and pepper. Bring to a simmer over medium-low heat, about 5 minutes. Discard rosemary and set the sauce aside.
Next, preheat the oven to 425˚F (220˚C). Line a baking sheet with parchment paper.
In a large bowl, combine ground beef and ground pork. Gently combine the meat. Add parmesan, Italian seasoning, garlic powder, onion powder, salt, pepper, egg and water. Mix until just combined. Do not overmix.
Divide the mixture into 30 portions. Roll them into meatballs. Place them on the prepared baking sheet. Bake in the oven for 12 - 14 minutes, or until cooked through.
In the meantime, bring the sauce back to a simmer over medium heat.
To serve, place some meatballs on serving plates. Top with a couple tablespoons cranberry sauce. Serve with mashed potatoes and extra sauce on the side. Top with Italian parsley if using.