Combine vinegar, water, salt, pepper, onion powder, bay leaves, cloves, celery flakes, thyme leaves and mustard seed to make marinade.
Place meat in this mixture, making sure it is covered with liquid. Cover; let stand at least 2 hours.
Add sugar. Simmer over low heat 3 hours or until tender.
Remove meat to platter. Keep hot.
Strain liquid to remove spices.
Return liquid to cooking pan; stir in gingersnap crumbs and raisins; cook, stirring until thick.
Serve with potato dumplings.