Directions

Place the chopped dark chocolate in a heatproof bowl.
In a small saucepan, heat the heavy cream over medium heat until it just begins to simmer.
Pour the hot cream over the chocolate and let it sit for a minute to melt.
Stir the mixture gently until the chocolate is completely melted and smooth.
Stir in the vanilla extract and let the mixture cool to room temperature.
Cover the bowl with plastic wrap and refrigerate for about 2 hours, or until firm.
Using a small spoon or melon baller, scoop out small amounts of the chocolate mixture and roll them into balls.
Press a small amount of chopped pistachios into the center of each ball and reshape them if necessary.
Roll each truffle in the unsweetened cocoa powder to coat.
Store the truffles in an airtight container in the refrigerator until ready to serve.

Variations & Tips
For a different twist, try using white chocolate instead of dark chocolate for a sweeter truffle. You can also experiment with different nuts, such as almonds or hazelnuts, for the filling. If you prefer a bit of spice, add a pinch of cinnamon or cayenne pepper to the chocolate mixture for a subtle kick. For a festive touch, roll the truffles in finely chopped pistachios or colorful sprinkles instead of cocoa powder.