Step 1

Combine sugar, pepper, and salt in a bowl. Apply rub to ribs, dividing evenly.

Step 2

Arrange ribs vertically in the bowl of a 5 to 7 quart slow cooker or separate into sections and lay flay in the bottom of a 5 to 7 quart slow cooker. Cook until the meat is tender but the racks are not falling apart, 3 to 4 hours on high or 6 to 7 hours on low. (There is no need to add liquid to the slow cooker.)