HEAT oven to 375ºF.
MIX first 5 ingredients and 1/4 cup cheese; shape into 18 meatballs. Place in 15x10x1-inch pan sprayed with cooking spray.
BAKE 15 min. or until done (160ºF). Meanwhile, cook spaghetti as directed on package, omitting salt. Heat sauce in large saucepan.
DRAIN spaghetti; place on platter. Stir meatballs into sauce; spoon over spaghetti. Top with remaining cheese.