Squeeze 5-6 oranges to yeild 3 cups of juice. In a large skillet, combine juice, 1/2 cup red-wine vingear and 1/4 cup molasses. Boil over high heat, skimming foam occasionally, until mixture is reduced to 1/2 cup; about 10-15 minutes. Reserve half the sauce for serving.
Place chicken breasts on a rimmed baking sheet lined with tinfoil. Season generously with coarse salt and cracked pepper. Brush with glaze.
Bake chicken, brushing with glaze and twice, at 20 minute intervals, until juices run clear when thickest part of meat is pierced with a fork - about 35-40 minutes. Serve hot with reserved glaze.