Grilled Baby Back Ribs with Citrus Barbecue Sauce | Williams Sonoma

Ingredients

• 1/4 cup sweet paprika 
• 2 Tbs. Old Bay Seasoning  
• 2 Tbs. chili powder 
• 1 to 2 tsp. cayenne pepper 
• 2 tsp. garlic powder 
• 1 Tbs. kosher salt  
• 1 Tbs. freshly ground black pepper 
• 1 Tbs. granulated sugar 
• 1/2 cup balsamic vinegar 
• 6 lb. baby back ribs 
• 1 small yellow onion, sliced 
• 1 cup fresh orange juice 
• 2 cups tomato ketchup 
• 1/4 cup fresh lime juice 
• 1/4 cup cider vinegar 
• 2 Tbs. firmly packed dark brown sugar 
• 1 Tbs. dry mustard 
• 1 Tbs. sweet paprika 
• 1 1/2 tsp. red pepper flakes 
• 1/2 tsp. garlic powder 
• 1/2 tsp. chili powder 
• 1 1/2 to 2 tsp. hot-pepper sauce, such as Tabasco 
• 1 Tbs. honey 
• 1 tsp. kosher salt  
• 1 1/2 tsp. freshly ground black pepper 
• 6 Tbs. (3/4 stick) unsalted butter