These rich chocolatey confections are an elegant end to a meal.
Bring heavy cream to a simmer in a small saucepan over medium heat. Remove pan from stove. Add chocolate and corn syrup, stirring until chocolate is melted. Fold in chestnuts; transfer to a medium bowl, and place in the refrigerator to chill until set, about 1 hour.
Using a dessert spoon, scoop out about 2 teaspoons of chocolate mixture, and, using fingers, form into roughly shaped balls; place on a parchment-lined baking sheet. Transfer to the refrigerator until cold and firm, 15 to 30 minutes.
Roll balls in confectioners' sugar or cocoa, coating completely, and store in covered container in the refrigerator or a cool dry place until ready to serve. This recipe can be made up to 5 days in advance. Do not roll in sugar or cocoa until just before serving.