Melt the chocolate and butter over a low heat or a double boiler until smooth and all chocolate has melted. If the mixture is too thick, add cream or milk. Remove from the heat.
Add the remaining ingredients except for sugar. Mix well. Let it cool.
Spread half the mixture onto plastic wrap or parchment paper and shape it into a log. Roll up the paper and twist the ends to seal. Roll back and forth on a work surface a few times to make the log evenly round. Repeat with the remaining chocolate mixture. Place the logs in the refrigerator until firm, about 1 hour.
Roll each log in the powdered sugar to coat. Brush off excess sugar. Wrap it up in kitchen twine to give it an authentic salami look (optional).
To serve, let the logs sit at room temperature for 10 minutes. Using a serrated knife, cut the logs into ½-inch thick slices. Keep refrigerated.
You can use Nilla wafers or digestive biscuits (about 1 cup) instead of biscotti and any nuts you have on hand.
Don't get tempted to form this into one large and thick salami. It will break and crumble when you try to cut it.