Minty Chocolate-Covered Slice-and-Bakes

Sift 2 cups flour and the cocoa into a medium bowl. In a large bowl, using an electric mixer on medium-high speed, beat the butter and sugar, stopping occasionally to scrape down the bowl, until light and fluffy, about 2 minutes. Add the egg yolks and extract. Beat until blended. Add the dry ingredients and the salt. Mix on low until just blended.

Turn the dough onto a lightly floured work surface. Divide in half. Roll each piece into a 12-inch-long log. Wrap each log in plastic and refrigerate until firm, at least 2 hours or overnight.

Arrange the racks in the top and bottom thirds of the oven; preheat to 350°. Slice the dough into 1/3-inch-thick rounds. Divide between 2 parchment paper–lined baking sheets, spacing about 1 inch apart.

Bake the cookies until the edges are set, about 12 minutes. Let cool on the sheets for 5 minutes, then transfer to wire racks to cool completely.

Place the mints in a gallon-size resealable plastic bag. Squeeze out the air, seal, then place inside another bag. Using a rolling pin, crush the mints. Set a wire rack inside a baking sheet. Place all the cookies on the rack. In a heatproof bowl set over a saucepan of simmering water, melt 2/3 of the chocolate, stirring occasionally. Off heat, add the remaining chocolate. Stir until melted. Spoon chocolate over each cookie. Sprinkle with the crushed mints. Let stand until set, about 1 hour. Store in airtight containers, layered between sheets of parchment.