1 rump roast — (3- to 4-pound) 1 cup water 1 cup white vinegar 1 medium-sized onion — sliced 1 lemon — sliced 10 whole cloves 6 peppercorns 3 bay leaves 2 tablespoons salt 2 tablespoons sugar 1 tablespoon olive oil 15 gingersnaps — finely crushed
Place roast in a large resealable plastic freezer bag. Combine water and next 8 ingredients; pour over meat. Seal and marinate in the refrigerator 8 hours, turning meat occasionally.
Remove meat from marinade, reserving 1-1/2 cups marinade; discard remaining marinade and bay leaves. Pat meat dry with paper towels. Heat oil in a large skillet over medium-high heat. Add beef; cook 3 to 4 minutes on each side or until thoroughly browned. Transfer beef to a 5-quart oval slow cooker; pour reserved marinade over meat.
Cover and cook on LOW setting 7 to 8 hours or until tender. Transfer roast to a serving platter, reserving juices in slow cooker; keep roast warm.
Add crushed gingersnaps to juices in slow cooker. Increase to HIGH setting; cover and cook 12 to 15 minutes or until gingersnaps are dissolved and gravy is thickened. Stir well. Serve roast with gravy.