1. Bring a large pot of salted water to a boil and cook the spaghetti until al dente. Reserve a little pasta water, then drain and set aside.

2. In a large bowl, mix the ground beef, breadcrumbs, egg, Parmesan cheese, garlic, Italian seasoning, salt, and black pepper until just combined.

3. Shape the mixture into 12 meatballs.

4. Heat olive oil in a large skillet over medium heat and brown the meatballs on all sides.

5. Pour the marinara sauce into the skillet and simmer the meatballs for 12 to 15 minutes, or until fully cooked through.

6. Sprinkle mozzarella cheese over the tops of the meatballs and let it melt gently.

7. Add black olive slices to each meatball to create monster eyes.

8. Toss the cooked spaghetti with some of the sauce, adding a splash of reserved pasta water if needed.

9. Plate the spaghetti, top with the cheesy monster meatballs, spoon over extra sauce, and finish with fresh parsley.