Prepare the Meatball Mixture: In a large mixing bowl, combine the ground beef, ground pork, panko crumbs, chopped onion, milk, Parmesan cheese, salt, eggs, beef seasoning, pepper, and garlic powder. Mix until well combined but avoid overmixing to keep the meatballs tender.

Stuff the Meatballs: Take a small portion of the meat mixture (about the size of a golf ball) and flatten it in your hand. Place a piece of mozzarella string cheese in the center and wrap the meat mixture around it, forming a ball. Ensure the cheese is fully enclosed. Repeat with the remaining mixture and cheese.

Preheat the Smoker: Preheat your smoker to 250°F (120°C) and add your choice of wood chips for flavor (hickory, mesquite, or cherry wood work well).

Smoke the Meatballs: Place the stuffed meatballs on the smoker grates or a wire rack. Smoke for 1.5–2 hours, or until the internal temperature reaches 165°F (74°C).

Prepare the BBQ Sauce: While the meatballs smoke, combine the BBQ sauce, honey, and brown sugar in a saucepan over medium heat. Stir until the sugar is dissolved and the sauce is slightly thickened. Remove from heat.

Glaze the Meatballs: During the last 20 minutes of smoking, brush the meatballs generously with the prepared BBQ glaze.

Plate and Enjoy: Once the meatballs are fully cooked and glazed, remove them from the smoker. Let them rest for 5 minutes before serving. Enjoy as an appetizer, main dish, or sandwich filling!