Mix the dry rub ingredients in small bowl. Sprinkle dry rub all over the pork shoulder, pressing it into the pork.
Combine the liquid ingredients and the garlic powder in a medium bowl and pour into a large Dutch oven. Place pork in the oven and tightly cover with aluminum foil then lid. Roast for 4 hours or until it's fork-tender and shreds easily.
Brush the roast with cooking liquid every hour.
Remove from oven and let stand until cool enough to handle. Shred the pork with a fork or tongs into bite size pieces.
Serve on hamburger buns topped with BBQ sauce and coleslaw.
Notes
Don't skimp on the cooking time - this BBQ pulled pork recipe really benefits from a long and slow cook in the oven so it's infused with flavor and becomes super tender.