Mix the brown sugar, smoked paprika, garlic powder, salt and pepper in a small bowl and rub it over the pork shoulder on all sides.

Lay the sliced onion in the bottom of a 6-quart crockpot and set the pork on top.

Pour the chicken broth around the sides of the pork, cover and cook on low for 8 to 10 hours, until the meat shreds easily with two forks and reaches 195 to 205 degrees.

Lift the pork onto a cutting board, shred with two forks, and discard any large pieces of fat.

Skim excess fat from the liquid left in the crockpot, then return the shredded pork to the pot.

Stir in the barbecue sauce until every strand is coated.

Keep on warm for serving, stirring occasionally so the bottom layer does not dry out.