In a large baking dish, combine the salt, black pepper, sugar, crumbled bay leaves, and ground cinnamon, creating a cure.
Place the ribs in the baking dish and toss them with the cure, coating them evenly. Sprinkle with the oloroso sherry. Cover with plastic wrap and refrigerate for 24 to 36 hours.
Preheat the oven to 250°F (120°C).
Remove the ribs from the cure. Rinse well and pat dry with paper towels. Place the ribs in a large Dutch oven with the lemon rind, cinnamon sticks, garlic, and whole bay leaves. Cover with the rendered pork fat.
Place the Dutch oven over medium heat and bring the fat to a bare simmer. Remove from the heat.
Cover and place in the oven for 2 hours, until the ribs are fork tender and the bones pull easily away from the meat. Remove from the oven.
Allow the ribs to cool to room temperature in the Dutch oven, and then place in the refrigerator to chill in the confit overnight.
In a small saucepan over medium–high heat, combine the PX sherry and the PX sherry vinegar. Bring to a boil and then reduce to a simmer. Simmer for 8 to 10 minutes, until the sauce’s volume is reduced to Á cup (80 mL). Remove from the heat and set aside.
Light a charcoal grill or heat a broiler on high heat (fair warning: The ribs will splatter a lot in an oven, so use caution!). Remove the ribs from the fat, wiping o. any excess. Place the ribs, meat-side down, and cook them for 10 minutes, until cooked through and starting to brown.
Glaze the ribs with the sauce on the bone side. Flip them over and glaze the other side. Continue cooking for 5 minutes, until nicely glazed and just charred a little in spots. Remove from the heat and serve.