dark chocolate balsamic truffles

When I saw Giada make this on her show, I fell in love instantly. I tried it her way, and was a bit bored with it, so I decided to kick it up a notch by rolling them in crushed salty pistachios. Wow, what a difference it made. I'm certain it was the extra salt in the pistachios and the actual crunchy texture that pulled it all together. This is a very rich truffle, so you only need a little bite to satisfy your chocolate craving. After all 70% cacao is an instant fix of chocolate cravings. These would be the perfect holiday gift to give to your friends and family that are foodies.
Note: I did not want to roll them into balls, I wanted a more rustic look since I added on the pistachios. I'm certain using crushed, salted almonds would work too. I don't know about peanuts though--I think the balsamic might not meld well with peanuts.

dark chocolate balsamic truffles
Adapted from Giada De Laurentiis

8 1/2 ounces good quality dark chocolate (70% cacao), chopped
1/4 cup heavy cream
2 teaspoons balsamic vinegar
1/2 cup cocoa powder (I did not roll them in cocoa powder, I rolled them in about ½ cup of chopped salty pistachios)

Melt the chocolate and cream in a double boiler over hot but not simmering water.
Place melted chocolate in a small bowl. Stir in the balsamic vinegar.
Cool the chocolate in the refrigerator for 1 hour. Remove from the refrigerator and let sit at room temperature for 2 hours, until firm but moldable.
Use a teaspoon to scoop out chocolate. Use your fingertips to shape into balls about the size of a cherry. Set the chocolate balls on a parchment-lined tray.
Place the cocoa powder in a small shallow dish. (this is where I used my chopped salty pistachios instead of the cocoa powder).
Place 6 truffles at a time in the cocoa powder (or the chopped pistachios) and roll the truffles around to coat, and return the coated truffles to the baking sheet.
Continue with the remaining truffles. Place the truffles in a serving dish or airtight package.