Place roast in slow cooker on HIGH until pork flakes off main roast with a fork, approx. 5–6 hours.
Combine soup, brown sugar, onion, salt, and pepper in saucepan over medium heat. Bring to a boil and continue boiling for several minutes to thicken. Pour over shredded pork, stirring thoroughly. Serve on toasted buns.
Recipe courtesy of Sharon Halverson, New Lisbon, WI.