Mix together the brown sugar, paprika, salt, cayenne, pepper, garlic and orange juice in a large bowl. Add the ribs and toss until coated evenly.
Cut an aluminum foil sheet that is 18 inches wide and 24 inches long and place on top of a baking sheet. Tip the ribs mixture onto the foil along with any extra juices from the mixing bowl. Fold the foil ends over the ribs, followed by the sides, and then seal the foil tightly to completely enclose. Bake until very tender, about 2 hours.
For the relish: Meanwhile, add the pineapple, cilantro, honey, chili powder, salt, jalapeño, red onion and lime zest and juice to a medium bowl and mix everything together. Set aside.
Remove the ribs from the oven and preheat the broiler.
Carefully open the foil pack to expose the ribs. Arrange the ribs so that the meaty top sides of the ribs are upright and place them under the broiler to caramelize, about 5 minutes.
Transfer the ribs to a platter or board, top with the cold pineapple relish and serve.