Using a knife, chop the chocolate into small pieces
Place the pieces into the bowl of a double boiler, over low heat, and allow the chocolate to melt completely. If you do not have a double boiler, you can melt the chocolate in the microwave, using 20 second increments, and being careful not to burn it.
Once the chocolate is completely melted, remove from the heat.
Work quickly to add the egg yolk, mixing it in with a wooden spoon.
Next, add the butter, crème fraîche, powdered sugar, and lastly, the alcohol of your choice. Stir well after each addition to fully incorporate. Place the mixture in the refrigerator for at least 3 hours, and preferably overnight.
When you are ready to form the truffles, place the unsweetened cocoa (or nuts, or sprinkles) in a short glass.
When the mixture is chilled, remove it from the refrigerator. Using a small spoon, scoop enough out to form a one inch ball.
Drop the ball of chocolate into the glass of cocoa and swirl it around until it is fully coated.
Remove the truffle from the glass using a fork.
You can place them in individual, paper candy cups, or directly into a metal tin.
Keep refrigerated.
