Remove ribs from packaging and place on a clean plate. Combine brown sugar, garlic powder, and pepper in a bowl. Pat mixture all over each rib and place in the crock pot.
Pour Dr Pepper over the ribs. Set the crock pot to low heat and cook 4 hours.
Remove liquid from crock pot and add barbecue sauce. Coat ribs with sauce and heat for 30 more minutes. Remove and serve hot. Enjoy!