In a small Mixing Bowl, combine all dry rub ingredients: 2 tbsp azúcar morena compactada, 1 tbsp pimentón ahumado, 1 tbsp sal kosher, 1 tbsp sal kosher, 1 tsp polvo de ajo, 1 tsp polvo de cebolla, 1 tsp comino molido, ½ tsp pimienta de cayena, and ½ tsp mostaza seca. Mix well until evenly combined.

Pat the 4 lb espaldilla de cerdo con hueso también llamada cerdo para desmenuzar completely dry with paper towels. Coat all sides evenly with the 2 tbsp mostaza amarilla utilizada como aglutinante para el condimento — this acts as a binder and won't affect the flavor. Then press the dry rub generously all over every surface of the pork, including the underside and any crevices.

For best results, place the rubbed 4 lb espaldilla de cerdo con hueso también llamada cerdo para desmenuzar on a plate, cover loosely with Plastic Wrap, and refrigerate for at least 1 hour or overnight. This allows the rub to penetrate the meat. If short on time, you can proceed immediately.

Preheat your Oven to 300°F. Place the 4 lb espaldilla de cerdo con hueso también llamada cerdo para desmenuzar fat-side up in a large Dutch Oven or deep Roasting Pan. Pour the ½ cup vinagre de sidra de manzana and ½ cup caldo de pollo into the bottom of the pan — this creates steam and keeps the meat moist.

Cover the Dutch Oven tightly with its lid (or cover the Roasting Pan tightly with two layers of heavy-duty Aluminum Foil). Place in the preheated Oven and cook low and slow for 7–8 hours, until the 4 lb espaldilla de cerdo con hueso también llamada cerdo para desmenuzar is completely fall-apart tender and an instant-read Meat Thermometer reads at least 200°F in the thickest part.

Carefully remove the 4 lb espaldilla de cerdo con hueso también llamada cerdo para desmenuzar from the Oven. Transfer it to a large Cutting Board or Baking Sheet and let it rest, uncovered, for 20–30 minutes. Reserve the pan drippings — don't throw them away!

Using two forks or your hands (once cool enough to handle), shred the 4 lb espaldilla de cerdo con hueso también llamada cerdo para desmenuzar, discarding the bone and any large pieces of fat. The meat should pull apart effortlessly. Skim the fat off the reserved pan drippings and pour a few spoonfuls back over the shredded meat to keep it moist and flavorful.

While the 4 lb espaldilla de cerdo con hueso también llamada cerdo para desmenuzar rests, make the BBQ sauce. Combine 1 cup catsup, ½ cup vinagre de sidra de manzana, 2 tbsp azúcar morena compactada, 1 tbsp salsa Worcestershire, 1 tbsp pimentón ahumado, 1 tsp polvo de ajo, 1 tsp polvo de cebolla, and 1 tsp salsa picante como Frank's (if using) in a small Saucepan over medium heat.

Stir the sauce and bring to a gentle simmer. Cook for 8–10 minutes, stirring occasionally, until slightly thickened. Taste and adjust seasoning — add more ½ cup vinagre de sidra de manzana for tang, more 2 tbsp azúcar morena compactada for sweetness, or more 1 tsp salsa picante como Frank's for heat. Remove from heat.

Toss the shredded 4 lb espaldilla de cerdo con hueso también llamada cerdo para desmenuzar with as much Grill sauce as you like — start with half and add more to taste. Serve piled high on toasted 8 panes de brioche o papas tostados with 2 cups ensalada de repollo comprada en tienda u hecha en casa on top, or serve the sauce on the side for dipping. Enjoy!