1. Preheat the oven to 350°F. Spray a cookie sheet or cake pan with nonstick cooking spray, or line with parchment paper.
2. In a large mixing bowl, combine all the meatball ingredients and mix until well-combined.
3. Using a large ice cream scoop, divide the meat into 12 even pieces, and roll between your hands to form meatballs.
4. Place on the cookie sheet, and bake for 28 – 30 minutes, until cooked through.
5. Remove from oven and set aside.

Make the Loaded Mashed Potatoes

1. Spray a 9×13 pan with nonstick spray. Set aside.
2. In a large mixing bowl, combine all the loaded mashed potato ingredients, and mix well.
3. Using a large ice cream scoop, scoop 12 large balls of mashed potato mixture, and line them up in the baking dish in rows of 3.
4. Using a small scoop or spoon, create a dip in the center of each potato ball for the meatball to sit on top.
5. Place the baked meatballs in the hole on top of the potato balls.

Make the Marinara Sauce

1. In a large saucepan, heat the olive oil over medium heat and add the onions. Cook the onions for 5 minutes, until softened, and then add the garlic. Cook for an additional 60 seconds.
2. Pour in the tomato sauce, and stir. Add the basil to the sauce and cook the sauce for 10 minutes.
3. Add the salt, sugar, pepper, thyme, and oregano, and continue cooking for an additional 5 minutes.
4. Place a scoop of sauce on top of each meatball, and top each mound with a slice of mozzarella cheese.
5. Place the pan in the oven and bake for 10 minutes.
6. Turn on the broiler to 500°F, and move the casserole to the top rack. Broil until the cheese is lightly browned, about 3 – 5 minutes. NOTE: Broiling is safest in metal baking pans. Glass and ceramic pans may break under high heat.
7. Remove and serve with your favorite side dish and bread.