Trim some of the thicker pieces of fat from the brisket if needed and cut the brisket into 1 to 2 inch cubes.
Put the brisket cubes in a large bowl or gallon size plastic bag and add the olive oil, brown sugar, BBQ seasoning, kosher salt, and pepper. Toss until evenly coated.
Set the Traeger pellet grill or smoker to 225 degrees, place the brisket bites on the grill grates for 2 hours, flipping them halfway through.
Remove the pieces of brisket and place in a 9×13 foil pan. Add the BBQ sauce, honey, and butter. Toss until evenly combined and cover with foil.
Place the covered foil pan back onto the Traeger or smoker (still at 225 degrees) for 1 1/2 to 2 more hours.