In a large saucepan or a slow cooker, combine the whole berry cranberry sauce, chili sauce, brown sugar, lemon juice, and garlic powder. Stir the mixture over medium heat until the cranberry sauce has melted and the ingredients are well blended and smooth.
Carefully add the frozen meatballs to the sauce. Stir gently to ensure every meatball is completely submerged or well coated in the crimson glaze. If you are using fresh, home cooked meatballs, ensure they are fully cooked before adding them to the sauce to prevent them from breaking apart.
Lower the heat and let the meatballs simmer for about 15 to 20 minutes. This allows the flavors to penetrate the meat and the sauce to thicken into a glossy, sticky coating. If you are using a slow cooker, you can set it to low for two to three hours instead.
Once the meatballs are heated through and the sauce is bubbling, transfer them to a festive serving platter. Garnish with a sprinkle of fresh chopped parsley or small sprigs of rosemary to mimic the look of a Christmas wreath. Serve them warm with toothpicks for easy snacking.
