Preheat the oven to 400°F. Place a wire rack over a sheet pan.
Mix together the brown sugar, salt, smoked paprika, garlic powder, chili powder, and black pepper.
Coat the pork chops generously on all sides with the seasoning mix, then place them on the wire rack.
Bake until the pork chops are about 15–20°F below 145°F. For chops around 1 inch thick, begin checking the temperature at about 15 minutes.
Turn the oven to broil, leaving the pan on the middle rack.
Brush barbecue sauce over the top, sides, and edges of the pork chops. Broil for about 5 minutes, watching closely.
Flip the pork chops, coat the other side and edges with barbecue sauce, then broil for another 5 minutes.
Check the internal temperature. If needed, continue flipping and broiling in short intervals until the pork reaches 145°F and the sauce is sticky, caramelized, and lightly charred.
Rest the pork chops for about 5 minutes before serving.