In a bowl, combine red wine vinegar, beef broth, sliced onion, minced garlic, brown sugar, whole cloves, bay leaf, salt, and whole black peppercorns. Whisk until thoroughly dissolved; place beef in a resealable bag and pour marinade over it. Seal and refrigerate for at least 4 hours, preferably overnight.

Remove the beef from the fridge and pat it dry. Heat vegetable oil in a skillet over medium-high heat. Sear the beef for 2-3 minutes on each side until golden-brown crust forms. Transfer the beef to the slow cooker.

Pour the reserved marinade over the seared beef in the slow cooker. Sprinkle crushed gingersnap cookies on top. Set the slow cooker to LOW for 8 hours or HIGH for 4 hours until fork-tender.

Carefully remove the beef from the slow cooker and place it on a cutting board. Strain the cooking liquid into a saucepan. Skim off excess fat. Mix flour with water to create a slurry and stir into the liquid over medium heat until thickened.

Slice or shred the tender beef and arrange on a platter. Drizzle gingersnap gravy over the beef. Serve with traditional sides like buttery egg noodles or red cabbage.