Cut ribs into single rib portions. Place ribs in a foil-lined large shallow baking pan. Bake, uncovered, in a 425-degree oven for 30 minutes, turning once halfway through baking.
Meanwhile, in a large bowl, combine ketchup, brown sugar, Worcestershire sauce and five-spice powder. Drain fat from ribs. Place ribs in bowl with ketchup mixture. Toss to coat ribs thoroughly. Return to baking pan. (If desired, ch ill up to 24 hours.).
To continue cooking, reduce oven temperature to 350 degrees. Bake 15 to 25 minutes longer or until tender.
Alternative Five-spice Powder: Combine 1/2 t. ground cinnamon, 1/4 t. ground ginger, 1/4 t. ground cloves, 1/4 t. ground anise, and 1/4 t. ground fennel.