01 - Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper for easy cleanup.
02 - In a large mixing bowl, combine breadcrumbs and milk. Let stand for 2 minutes. Add the ground beef, ground pork, egg, chopped onion, minced garlic, salt, black pepper, and smoked paprika. Mix gently until just combined; avoid overmixing for tender meatballs.
03 - Shape the meat mixture into 1 1/2-inch (4 cm) diameter balls. Arrange them evenly on the prepared baking sheet. Bake for 18–20 minutes, or until the meatballs are nicely browned and cooked through.
04 - While the meatballs are baking, prepare the glaze. In a saucepan over medium-high heat, whisk together the root beer, ketchup, brown sugar, apple cider vinegar, Worcestershire sauce, Dijon mustard, and chili flakes (if using). Bring the mixture to a boil, then reduce the heat to low and simmer for 10–12 minutes, stirring occasionally, until the glaze has thickened.
05 - Transfer the baked meatballs to a large skillet or saucepan. Pour the prepared root beer glaze over the meatballs. Toss gently to ensure each meatball is evenly coated. Simmer on low heat for 5 minutes, stirring occasionally, until the meatballs are glossy and heated through.
06 - Serve the glazed meatballs warm. Garnish with chopped fresh parsley, if desired.