1/4 cup packed brown sugar
1 teaspoon salt
1/2 teaspoon pepper
3 tablespoons liquid smoke
2 cloves garlic, finely chopped
1 medium onion, sliced
1/2 cup cola
1 1/2 cups barbecue sauce
Spray inside of 4- to 5-quart slow cooker with cooking spray.
Remove inner skin from ribs. Mix brown sugar, salt, pepper, liquid smoke and garlic; rub mixture into ribs. Cut ribs into 4-inch pieces. Layer ribs and onion in slow cooker. Pour cola over ribs.
Cover and cook on low heat setting 8 to 9 hours or until tender. Remove ribs from slow cooker. Drain and discard liquid.
Heat coals or gas grill. Place ribs on grill. Brush with barbecue sauce. Cover and grill 4 to 6 inches from medium heat 15 minutes.