Preheat oven to 400 degrees F. Layer onions in a large cast iron skillet or 9x9 baking dish. Drizzle with olive oil. Set aside.
In a small bowl, combine the kosher salt, garlic powder, onion powder, chili powder, paprika and pepper.
Sprinkle both sides of the pork chops with the bbq rub. Place the seasoned chops on top of the onions. Bake for 15 minutes.
Remove from the oven and brush both sides of the chops generously with barbecue sauce. Bake another 5 minutes. Remove from oven and let rest for 3 minutes before slicing. Top with onions when serving.