At Christmas time we were always thrilled if we received a chocolate orange. If you coarsely chop one up and add it to this tender, buttery cake you end up with a cake that will be just as well received as a chocolate orange. You can marbleize this cake or leave it as a vanilla-orange batter, with the Chocolate Orange pieces, dotted throughout the cake. Not as heavy as a pound cake, but moist and delicious. I highly recommend.