Just in time for those of you who have holiday baking to do, here's a festive cookie recipe that Julie made for my book group's holiday party, and they came out delicious. They are exactly like the Mystic Mints of the 1970s, which my sister and I used to devour. (I found a Facebook page that is hoping to get enough "likes" to urge Nabisco to start making them again.)
My photos came out lousy, so I will use Sarah Coates's lovely photo over at Food52, where I found the recipe in the first place:
So, you get a nice chocolate cookie on the bottom, then a thin layer of peppermint creamy stuff, and then the whole thing is dipped in melted chocolate. I'm not a huge fan of peppermint, but I still love these (and also Girl Scouts' Thin Mints, of course). Instead of peppermint extract, Julie used peppermint oil, which is much more concentrated, so she used just a scant ⅛ teaspoon. I found them a wee bit too pepperminty still, so I think just a few drops would be perfect.
Homemade Mystic Mint Cookies
4 ounces butter, at room temperature
½ cup granulated sugar
¼ cup cocoa powder
1 cup all-purpose flour
1½ cups powdered sugar
1 tablespoon water
½ teaspoon peppermint extract
4 ounces milk chocolate
2 6 ounces dark chocolate (A girl after my own heart, Julie used all dark chocolate instead of a mixture of dark and milk. There was barely enough melted chocolate to coat all 20 cookies, so consider melting another ounce or so.)
1 tablespoon coconut oil or vegetable oil
Cream together the butter and granulated sugar until light and fluffy. Scrape down the bowl, add the egg, and continue beating until the egg is incorporated and the mixture lightens in color. Add the cocoa powder to the egg mixture and beat until there are no lumps. Finally, fold in the flour until it is all incorporated.
The dough will be very soft. Turn it out onto a piece of parchment paper, roll it into a log about 1½ inches thick, and wrap the dough. (Julie said it stuck to the paper a bit.) Place the log in the freezer to chill for at least 30 minutes.
Preheat the oven to 350° and line two baking sheets with Silpats or parchment paper. When the dough is finished chilling, take it out of the freezer and slice the log into rounds just under ½ inch thick; you should get about 20. Place the cookies on the baking sheets and bake for 10 minutes. (There's no doneness cue here, but they will start to smell good!) Remove from the oven and set aside to cool completely on the baking sheets.
To make the mint filling, stir together the powdered sugar, water, and peppermint extract. The mixture should be very thick, like the texture of playdough. (Julie's was somewhat crumbly, so she added a tiny bit more water.) Take a scant teaspoon of the mint filling and put it atop each cookie, using your fingers to pat and smooth it down to cover the top but stopping shy of the edge of the cookie.
To coat the cookies, melt the chocolate and the oil together in the microwave in short bursts, stirring well between each burst until you have a smooth mixture. Let the melted chocolate cool slightly, and set a rack over a sheet of foil or parchment paper.
Dip each cookie in the chocolate, coating it completely. Set them on the rack to drip and set. (We put the rack and foil right in the fridge.) Once they're set, store them in a covered container in the fridge, where they'll keep well for at least a week. They also freeze beautifully for up to a month—and even taste great straight out of the freezer.