This is a great one - I've made it many times. I use a different method, however - I melt the first three ingredients together over a double boiler. (I use Ghirardelli's 60% bittersweet chocolate. Also, I mix in a little vanilla extract after removing from the heat):
GHIRARDELLI SINFUL CHOCOLATE TRUFFLES Ghirardelli Sinful Chocolate Truffles Recipe : : Food Network