Makes about 24 truffles
8 ounces bittersweet or semisweet chocolate or 12 ounces milk chocolate, chopped
3/4 cup heavy cream
2 tablespoons cognac or other or 1 teaspoon pure vanilla extract
1/4 cup unsweetened cocoa powder
Place the chocolate and cream in a medium bowl or in the top of a double boiler. Sit the chocolate over a pot or the bottom of a double boiler with at least an inch of simmering water. Gently stir until the chocolate is melted and the mixture is smooth. Remove from the heat and stir in the cognac or vanilla.
Pour the ganache into an 8-by-8-by-2-inch baking pan and freeze for about 30 minutes, until the ganache is the consistency of fudge. Use a melon baller or small spoon to form the ganache into rough, tablespoon-sized rounds. Place the rounds on a baking sheet lined with parchment or wax paper. Refreeze for about 15 minutes. Remove from the freezer and, working quickly, form each round into a 1-inch ball.
Either sift the cocoa over the truffles, turning them for even dusting, or roll truffles in a dish of the cocoa. Refrigerate for up to 2 weeks. Bring to room temperature before serving.
Variations
For Ginger Truffles: Use 1 tablespoon powdered ginger in place of the cognac.
For Lavender Truffles: In a small saucepan over medium-high heat, combine 2 tablespoons of chopped lavender with 3/4 cup cream and heat to barely simmering; remove from the heat and set aside for 5 to 10 minutes before straining through a fine-mesh strainer. Use this lavender-infused cream in place of the cream.
For the Milk Chocolate Truffles with Cocoa Nibs: Use 3 tablespoons of cocoa nibs in place of the cognac.