HEAT oven to 350ºF.
PREPARE stuffing as directed on package. Let stand 5 min.; mix lightly.
PLACE meat, cut-sides up, on work surface; cover with stuffing to within 1/2 inch of edges. Roll up, jelly-roll fashion, starting at one short end. Place, seam-side down, in pan sprayed with cooking spray.
BAKE 1 hour. Mix syrup, mustard and rosemary; spread over meat. Bake 20 min. or until meat is done (160°F). Let stand 15 min. before slicing.