Rub the ribs all over with the sesame oil; season generously with five-spice powder, salt, and pepper. Arrange the ribs in a single layer in a shallow roasting pan and roast for 2 to 2 1/2 hours.
To prepare the pineapple glaze: In a saucepan over medium heat melt the butter and add the pineapple chunks; saute for 3 minutes. Add the soy sauce, rum, hoisin sauce, ketchup, vinegar, brown sugar, chile, garlic, and ginger. Bring to a slow simmer and cook, stirring, until thickened, about 20 minutes. Pull out the ginger pieces. Pour the glaze into a blender and puree until smooth.
In the last 30 minutes of cooking, baste the ribs with some of the glaze. When they are done, the pork will pull away from the bone and you will see about 1/2-inch of bone showing. When you are ready to eat, baste the ribs with more glaze and stick them under the broiler for 5 to 8 minutes to give the ribs a nice crust. (Watch them carefully as they can easily burn.) Separate the ribs with a cleaver or sharp knife, pile them onto a platter, and pour on the remaining sauce. Sprinkle with sesame seeds and chopped cilantro before serving.