Chocolate Mint Wafers

• 1/2 cup (1 stick) unsalted butter, room temperature
• 1/2 cup sugar
• 1 large egg, room temperature
• 1 cup cocoa powder
• 1/2 cup plus 2 tablespoons all-purpose flour
• Confectioners’ sugar for rolling
• 1/4 cup heavy cream
• 12 ounces semisweet chocolate
• 2 to 3 drops peppermint oil (or 1/2 teaspoon peppermint extract)

Instructions:
1. In the bowl of an electric mixer fitted with the paddle attachment, cream the butter and sugar until completely smooth, about 3 minutes. Add the egg, and continue mixing until well combined. Whisk together the cocoa powder and the flour, then add to the butter mixture. Scraping the sides of the bowl down, continue mixing until just combined. Divide the dough in half, and wrap each half in plastic wrap. Shape into a small disc, and refrigerate at least 1 hour until firm. (The dough can also be made a day ahead and refrigerated overnight.)
2. Heat the oven to 350°. Line two baking sheets with Silpat nonstick baking mats or parchment paper. Lightly sprinkle a clean work surface with confectioners’ sugar. Place the chilled dough on the work surface. Roll out dough to 1/8 inch thick. (Save the scraps to refrigerate, and roll out again.) Using a 2-inch cookie cutter, cut out the cookies, and place on the prepared baking sheets, about 1/2 inch apart. You should be able to fit about 35 cookies on a baking sheet. Bake until you can smell the chocolate, about 12 minutes. Remove to a rack to cool.
3. Meanwhile, bring cream to a boil in a small saucepan over medium-high heat. Very finely chop 6 ounces of chocolate, and add to hot cream. Stir with a rubber spatula until the chocolate is melted and smooth. Add the peppermint oil. Let cool slightly, about 10 to 15 minutes.
4. Transfer ganache to a pastry bag fitted with a #11 tip. Pipe out quarter-size amounts of chocolate, about 1 teaspoon each, onto the center of half the wafers. Top with the remaining wafers. Chill in the refrigerator until firm, about 10 minutes.
5. Melt the remaining chocolate in a double boiler over medium heat. Let cool slightly. Dip one side of the cookie sandwich to coat. Remove the excess chocolate by scraping the cookie against the side of the bowl. Return to the refrigerator until the chocolate is set, about 10 minutes.

Makes about 3 dozen