Place all ingredients except the nuts in a medium bowl. Set bowl on pan of simmering water; do not allow bowl to touch water. (Or place it in top of double boiler.) Heat until melted, smooth and warm. Watch closely and stir often. Remove from heat, cover and refrigerate overnight.
These truffles are very soft; they must be cold for shaping and rolling. Working quickly, roll the refrigerated mixture into smooth 1-inch balls. Place on parchment or waxed paper. Roll the truffle balls in the finely ground nuts. Refrigerate for up to one week.
Remove from refrigeration about 10 minutes before serving. Refrigerate any remaining truffles.