Spray the slow cooker with cooking spray. Add the pork roast. In a small bowl, combine the hoisin sauce, garlic, ginger, chili paste, rice wine, soy sauce, and sesame oil. Whisk in the cornstarch. Pour the sauce over the pork.
Cook in slow cooker for 8 hours on low heat. Transfer pork to a platter; tent with foil and let stand 10 min. Pour the cooking liquid into a bowl and let stand for 10 min., then skim any fat from the surface. Slice the pork and arrange on a platter. Sprinkle with scallions and cilantro. Serve sauce on the side.