How to Make It
Preheat the oven to 275°. Set a rack on a rimmed baking sheet. Season the ribs with salt and pepper and set meat side up on the rack. Bake for 1 hour and 30 minutes.
Meanwhile, in a medium saucepan, heat the olive oil. Add the shallots and half of the garlic and cook over moderate heat, stirring, until softened, about 5 minutes. Add the cherries, sugar and 2 1/2 tablespoons of the vinegar and cook until the cherries burst, 5 to 7 minutes. Transfer to a blender and let cool slightly, then puree until smooth. Return to the saucepan and cook over moderately high heat, stirring often, until reduced to 1½ cups, about 7 minutes. Let the barbecue sauce cool, then stir in the Sriracha and season with salt and pepper.
In a medium bowl, whisk the cherry juice with the stock and the remaining garlic and 2 tablespoons of vinegar. Stack four 18-inch-long sheets of heavy-duty foil in 2 piles on a work surface. Set 1 rack of ribs meat side down in the center of each. Fold up the foil to form 4 sides and pour half of the juice mixture on each rack. Wrap the ribs tightly in the foil, then transfer the packets to the rack and bake for 1 hour and 30 minutes, until the ribs are very tender. Remove from the oven and open the packets. Let stand for 5 minutes, then discard the cooking liquid and foil. Return the ribs to the rack meat side up.
Increase the oven temperature to 450°. Brush the ribs liberally with the barbecue sauce and bake, turning and brushing occasionally with the sauce, for 10 to 12 minutes, until nicely glazed. Let rest for 5 minutes, then cut in between the bones and serve.