4–6 lb. boneless pork shoulder roast
1 12-oz. bottle or can, plus 1 can root beer, divided
1 c. ketchup
2 c. packed light brown sugar
2 tbsp. molasses
1/4 c. Worcestershire sauce
Juice of 1 lime
1/2 tsp. garlic powder
1/2 tsp. onion powder
12 brioche sandwich rolls
In a large slow cooker, combine pork and root beer. Cook on high until the pork is very tender and shreds easily with fork, 5 to 6 hours. Make the barbecue sauce 30 minutes before serving. In a medium saucepan over medium-low heat, whisk together root beer, ketchup, sugar, molasses, Worcestershire sauce, lime juice, garlic powder, and onion powder. Simmer until the flavors meld and the sauce reduces slightly, 8 to 10 minutes. If there is a lot of excess liquid in the slow cooker, drain the pork before shredding. Using two forks, shred the pork. Add about 3/4 of sauce to the meat and mix until pork is evenly coated. Scoop pork onto bottom halves of brioche buns, garnish with more sauce (if desired) before topping with top brioche halves.