Lightly spray slow cooker with nonstick cooking spray.
Place ribs in the bottom of slow cooker.
Combine beef broth, soy sauce, maple syrup, honey, barbecue sauce and dry mustard in a mixing bowl. Pour over ribs.
Cover and cook on low for 6-8 hours or high for 3-4 hours.
Remove ribs from slow cooker and brush ribs with extra BBQ sauce and put under the broiler for 5 minutes on a foil-covered baking sheet to get them brown and bubbly.