In a large mixing bowl, combine ground beef, breadcrumbs, eggs, milk, chopped onion, minced garlic, and seasonings like salt, pepper, and smoked paprika. Use your hands to mix everything until well combined, then shape the mixture into meatballs about 1–1.5 inches in diameter.

If you prefer an extra layer of flavor, heat a skillet over medium-high heat and add a touch of oil. Gently place the meatballs in the hot skillet and brown them on all sides, about 5 minutes total, until they have a nice golden color. Once browned, transfer them to the slow cooker.

In a separate bowl, whisk together your barbecue sauce, pineapple juice, brown sugar, soy sauce, apple cider vinegar, and optional spices like garlic powder and ground ginger. Blend these ingredients thoroughly until smooth.

Place the meatballs in your slow cooker, ensuring they're evenly distributed. Scatter the pineapple chunks over the meatballs, then pour the prepared sauce evenly on top.

Cover your slow cooker and set it to LOW for 3–4 hours or HIGH for 1.5–2.5 hours, until cooked through.

For a thicker sauce, in the last 20–30 minutes, whisk together some cornstarch and water to form a slurry. Stir it into the sauce in the slow cooker and let it cook uncovered.

Once cooked, serve the meatballs warm, garnished with sliced green onions or fresh parsley.