Heat oven to 300°F. Line broiler pan with foil; spray foil with cooking spray. Sprinkle riblets with salt; arrange in single layer on pan. Pour apple cider into pan. Cover tightly with foil. Bake about 3 hours or until tender and no longer pink next to bones.
In 1-quart saucepan, mix ketchup, honey, soy sauce, hoisin sauce, sesame oil and five-spice powder. Heat to simmering over low heat; simmer 10 minutes, stirring occasionally. Brush ribs with half of the sauce; bake uncovered 30 minutes longer or until sauce thickens on ribs. Serve with remaining sauce. Sprinkle with green onions.