Mix beef, pork, breadcrumbs, eggs, milk, Parmesan, garlic & onion powder, salt, and black pepper in a bowl.
Roll the meat mixture into small balls about 1-2 inches in diameter.
Place the meatballs on a smoker rack and smoke for 2-3 hours at 225°F/107℃ or until they reach an internal temperature of 165°F/74℃.
Mix ketchup, sugar, vinegar, mustard, Worcestershire sauce, garlic, salt, and pepper. Simmer for 10-15 mins, stirring.
Brush the homemade BBQ sauce over the meatballs during the last 30 minutes of cooking, turning occasionally to coat them evenly.
Serve the smoked meatballs hot with extra BBQ sauce and your choice of sides, such as roasted vegetables, mashed potatoes, or coleslaw.