Preheat the oven to 425ºF. Spray a baking sheet with non-stick cooking spray.

Place the turkey in a large mixing bowl. Grate the onion into the bowl. Mince 3 cloves of garlic and add to the turkey along with the egg, bread crumbs, Parmesan cheese, salt, and pepper. Mix to combine. Roll into 20 small balls. Cut the olives in half crosswise. Make a small indentation into the meatballs and insert half an olive into each with the cut side facing out. Place meatballs on the prepared baking sheet. Bake for 10-15 minutes.

While the meatballs are baking, cook the black bean spaghetti according to the package directions. Drain.

Heat the olive oil in a large skillet over medium heat. Crush the remaining 2 garlic cloves and add to the hot oil. Cook, stirring, for 30 seconds. Remove and discard the garlic. Add the drained spaghetti to the oil and toss to coat. Arrange the eyeball meatballs on top of the spaghetti and serve.