Chocolate Mint Wafers

1. In the bowl of an electric mixer fitted with the paddle attachment, cream butter and sugar on medium speed until completely smooth, about 3 minutes. Add egg, and continue mixing until well combined.

2. In a medium bowl, whisk together cocoa powder and flour.

3. Add flour mixture to butter mixture; mix on low speed until combined, scraping down sides of bowl once. Divide dough in half; wrap each half in plastic. Flatten each half into a disk; chill until firm, at least 1 hour.

4. Preheat oven to 350 degrees. Line two baking sheets with Silpat baking mats or parchment paper. Set prepared pans aside.

5. Lightly sprinkle a clean work surface with confectionersâ?? sugar. Roll out dough to an 1/8-inch thickness. Using a 2-inch cookie cutter, cut out cookies, and transfer to prepared baking sheets, spacing cookies 1/2 inch apart. Chill any trimmings, and roll out again.

6. Bake the cookies until you can smell chocolate, about 12 minutes. Transfer the baking sheets to a wire rack to cool.

7. Bring cream to a boil in a small saucepan set over medium-high heat. Add chocolate to hot cream. Stir with a rubber spatula until chocolate has melted and mixture is smooth. Add peppermint oil. Remove from heat; let ganache cool slightly, about 20 minutes.

8. Transfer chocolate to a resealable plastic bag; seal, and cut off one corner at an angle. Pipe about 1 teaspoon onto the center of half of the wafers. Top with the remaining wafers. Chill the assembled cookies until firm, about 10 minutes. Store in an airtight container up to 2 days.

Cook's Notes

Peppermint oil is very potent, so use only two to three drops, depending on how strong you want the filling to be. You can substitute peppermint extract, available at grocery stores. When preparing the ganache, chop the chocolate very finely so it melts with ease.