Preheat your oven to 300 degrees Fahrenheit.
Let the pork shoulder rest at room temperature for about 1 1/2 hours.
This helps to ensure even cooking.
Mix all the dry spices together in a bowl: black pepper, paprika, garlic powder, onion powder, salt, chili powder, cumin, and brown sugar.
Rub this mixture all over the pork shoulder until it’s completely covered.
Place the seasoned pork in a braising pan.
Add the BBQ sauce, apple cider vinegar, and sliced onions to the pan.
Make sure everything is well combined around the meat.
Cover the braising pan tightly with a lid or aluminum foil.
Braise in the oven for 3 hours until the pork is fork-tender.
Check for doneness by pulling at the meat with a fork.
Remove the meat from the oven.
Use two forks to shred the pork into fine pieces.
Add some of the braising liquid back into the meat for extra flavor.