Preheat your pellet grill or smoker for 250 degrees F. Add your choice of wood.
Combine BBQ sauce, ketchup, molasses, Dr. pepper, brown sugar, and BBQ rub in a medium bowl. Set aside.
Heat olive oil in a 12-inch cast-iron skillet. Cook onions and garlic until translucent over medium heat.
Add baked beans to the pan, then pour barbecue mixture over the top. Add your meat, and stir through.
Place the entire pan into your smoker, close the lid, and let it cook for 2 hours.
Beans will thicken a bit and take on a darker color when done.
Remove pan from the smoker, and let it sit for 15 minutes before serving.
Store leftovers in an airtight container in the refrigerator for 4-5 days. Freeze for up to 3 months in vacuum-sealed bags.