HEAT oven to 375ºF.
MIX meat, stuffing mix, water, eggs and 1/4 cup spaghetti sauce. Shape into 16 (2-inch) meatballs. Insert 1 cheese piece into top of each meatball, with end of cheese piece just showing at top. Place on baking sheet. Top each with olive slice to resemble eyeball.
BAKE 20 to 25 min. or until meatballs are done (160ºF). Meanwhile, cook spaghetti as directed on package, omitting salt and heat remaining spaghetti sauce as directed on jar.
DRAIN spaghetti. Serve topped with meatballs and sauce.