Preheat oven to 275 degrees F.

In a small bowl, mix together the barbecue rub and brown sugar. Set aside.

Trim the thick layer of fat down to a consistent 1/4 inch. Poke holes all over the brisket roast with a fork. Rub the rub into the brisket roast on all sides.

Wrap bacon slices around the roast the best you can (it doesn't need to be perfect!). Place in large baking dish, fat side down. Cover the dish with foil and bake for 4 hours.

Remove baking dish from oven. Pour off juices into a heat proof bowl. Remove bacon from roast and set aside. Flip roast over so it's fat side up. Cover with foil and return to oven for an additional hour.

While the roast is continuing to cook, finish bacon off in a saucepan. Set aside. In the bacon fat in the sauce pan, cook the diced onion over medium heat for about 10-15 minutes, until it has softened. Tear the bacon into 1/2 inch pieces Add the juices from the baking pan, barbecue sauce, and bacon to the saucepan. Simmer for 15 minutes, or until the sauce has reduced and thickened.

Remove the baking dish from the oven. Coat the brisket with a layer of the prepared sauce. Return to oven and set oven to broil. Broil for about 5 minutes, or until fat turns crispy.

Remove from oven and let brisket rest for about 5 minutes. Cut into 1/4 inch slices against the grain. Serve with additional sauce.