HEAT oven to 400°F.
MIX first 6 ingredients until well blended; shape into 24 meatballs, using about 2 Tbsp. meat mixture for each. Place in 15x10x1-inch pan sprayed with cooking spray.
BAKE 15 to 17 min. or until meatballs are done (160ºF). Meanwhile, mix barbecue sauce and dressing.
FILL buns with lettuce and meatballs; serve with sauce.