Rich Chocolate Truffles

Add these rich chocolate truffles to a holiday basket for a little added extravagance!
They may be formed into balls and rolled in cocoa, sprinkles or chocolate, or piped through a pastry bag onto waxed paper.
This recipe yields about 50 truffles and I recommend making multiple batches instead of doubling the recipe for best results. 4 ounces unsweetened chocolate, chopped 4 ounces semisweet chocolate, chopped 1/3 cup water 12 tablespoons (1&1/2 sticks) butter or margarine, at room temperature 2 cups powdered sugar, sifted 1 large egg yolk, at room temperature 2 tablespoons rum Unsweetened cocoa powder, chocolate sprinkles, melted or chopped chocolate, for garnish Place both chocolates and water in a medium pan. Melt over low heat, stirring constantly. Cool to room temperature. Mix the butter, powdered sugar, egg yolk and rum in a mixing bowl with electric mixer until light and fluffy. Mix in the melted chocolate mixture. To make rosettes, line a baking sheet with waxed paper or bon bon papers. Spoon the truffle mixture into a pastry bag fitted with a large (1&1/2" ) star or rosette tip. Pipe a large rosette onto the paper or into each cup and refrigerate or freeze until set. To shape into balls, refrigerate mixture until firm enough to roll into 3/4" balls. Roll the balls in cocoa, sprinkle, or finely chopped chocolate or dip in melted chocolate to cover. Refrigerate or freeze until firm. The truffles may be stored in an airtight container in the refrigerator for up to 3 weeks, or they may be frozen. Serve chilled.