Wash yams and cut in half. Boil in water to cover until tender. Drain and cool. Remove peelings. Place halved yams in 9 x 13 inch glass dish. Dot with butter on top of yams. Drizzle red Karo syrup on top and sprinkle yams with brown sugar. Optional vanilla or cinnamon on top. Bake 1/2 hour at 325-350 degrees until moisture is candied.