In a large mixing bowl, combine the ground beef, breadcrumbs, chopped parsley, grated Parmesan, egg, garlic powder, onion powder, salt, and black pepper. Mix gently but thoroughly without overmixing.
Form the mixture into small, bite-sized meatballs about 1 to 1.5 inches in diameter. Place them on a baking sheet or plate.
Optional: Brown the meatballs in a skillet over medium heat with a little oil, about 2 minutes per side, for extra flavor and a crust.
In a bowl, whisk together the cranberry sauce, chicken broth, soy sauce, black pepper, and dried thyme to make the glaze.
Place the meatballs in the slow cooker and pour the glaze over them. Stir gently to coat evenly. Cover and cook on low for 3-4 hours or on high for 1.5-2 hours until meatballs are tender and glaze thickens slightly.
Give the meatballs a final stir before serving. Serve warm with toothpicks for easy party snacking.