Welcome to the coffee drinking world...it only gets better
Probably the simplest thing to do (one I personally don't prefer) would be to add chocolate sauce flavoring and stir it in. However, if you are looking for a very slight malt, chocolate like taste, a quality roasted fair trade organic Honduras Cocosam or fto Guatemala Antigua will produce this type of flavor without anything added in.
Good quality, well roasted arabicas from origins such as Central or East Java or Flores (all Indonesian coffees of course), have some great chocolate cupping qualities. The Java's are more bitter chocolate, while the Flores a sweeter, more syrupy chocolate in the cup.