Preheat the oven to 350°F (175°C).
In a mixing bowl, combine the ground beef, breadcrumbs, milk, chopped onion, minced garlic, eggs, BBQ sauce, Worcestershire sauce, salt, pepper, and smoked paprika. Mix well until combined.
Form the meat mixture into a loaf and place it in the center of the baking dish.
In another bowl, mix the sliced potatoes, sour cream, shredded cheddar cheese, milk, melted butter, garlic powder, onion powder, salt, and pepper until well combined.
Spread the potato mixture evenly around the meatloaf in the baking dish.
Cover the baking dish with foil and bake in the preheated oven for 45 minutes.
After 45 minutes, remove the foil and bake for an additional 15 minutes, or until the meatloaf is cooked through and the potatoes are tender.
Remove from the oven and let it rest for a few minutes. Garnish with chopped green onions before serving.