In 3 1/2- to 4-quart slow cooker, mix beef, onions, broth, vinegar and bay leaves.
Cover; cook on Low heat setting 7 to 9 hours.
About 15 minutes before serving, cook noodles as directed on package. Remove bay leaves from beef mixture. Stir in crushed cookies and brown sugar. Cover; cook on Low heat setting 15 minutes longer or until mixture is bubbly and thickened. Serve beef mixture over noodles; sprinkle with parsley.