Combine red wine, red wine vinegar, 2 cups water, onion and bay leaves and place in a large plastic bag that can be sealed
Place top round or rump roast in marinade, seal the bag and place in the refrigerator overnight
When ready to prepare, remove roast and strain the marinade to reserve juice but get rid of onion and spices
Reserve the marinade
Heat olive oil in a large stock-pot and brown onions, carrots, and celery
Sprinkle with flour and cook until flour starts to brown
Add 2 cups of reserved marinade and 1/2 cup of water
Place roast in marinade and vegetable mixture and cover
Simmer over low heat for 2 hours
Remove 2 and 1/2 cups of liquid from the roast stock pot and place in a saucepan with the crushed gingersnaps
Heat for about 10 minutes over medium heat until mixture starts to thicken
Slice roast and serve with gingersnap sauce