Cut the ribs between the bones to give individual ribs. Put the in a single layer in the bottom of the slow cooker.
Mix together the hoisin sauce, honey, soy sauce, rice wine, Chinese five spice, ginger and garlic. Pour on top of the ribs and turn them over a little to coat. You should have a thin layer of sauce over the top and a slight 'puddle' around the ribs (see photo above). Put the lid on and cook on low for 6-7 hours.
After they are cooked and tender, but not falling off the bones too much, carefully remove the ribs from the slow cooker and place on a foil-lined baking sheet/tray. Pour the sauce into a small pan and simmer for a few minutes to reduce slightly. Pour a little over the ribs and put under the broiler/grill for a couple minutes to caramelize. Serve with some more of the sauce on the side, if you like.
Note - you can easily double this recipe for a full rack of ribs (or more) - you may want to increase the cook time to 7-8 hours and add a little water to the sauce as it cooks if there isn't enough to keep the ribs moist.