Who knew Thin Mints were so easy to make? Seriously, they are just about impossible to ruin. Work the dough to death, and — unlike gluten-containing cookies — they still turn out perfectly. You sold yet? Where things get trickier are the ingredients — I call for both black onyx cocoa powder and peppermint oil. Oh, Heather . . .
The black cocoa powder is absolutely key to making Thin Mints as dark and chocolatey as the ones from the box (or homemade Oreos — don’t worry, we’ll get there); so totally worth seeking out. I’d been meaning to look up sources and even maybe order, despite loathing shipping charges, some black cocoa for quite some time. Like, before Pinterest went mainstream and recipes for D.I.Y. Oreos and Thin Mints got repinned like crazy. And then, by happy coincidence, I ran into Savory Spice Shop when visiting Santa Rosa with my family in July. Lo and behold they had exactly what I needed, so I returned home with that and many more items. There are about twenty locations — some company-owned, others franchised — in eight states, so maybe you’re lucky enough to have one nearby to peruse. But luckily for everyone else, they sell the requisite cocoa through their online shop.
As for the peppermint oil, I used one by NOW Foods purchased through Drugstore.com. The warning about needing to dilute the oil got me a bit nervous, but (1) it’s the brand recommended by Chow in the original recipe and (2) a whole stick of butter is used in the recipe — it’s not like I’m suggesting you massage the stuff directly on your tastebuds. If you’re tempted to increase the amount of oil called for, resist! The cookies themselves are very minty; after two days of Thin Mint baking my apartment smells absolutely fantastic. Probably because I rolled them directly on my butcher block counters — quite likely not one of my better ideas, but whatever. I love the scent. Just keep that in mind when you roll yours out, ok?
Despite their minty flavor and easily-melted-in-summer-heat chocolate exterior, I think these are perfectly suited to the summer. Not only is the flavor inherently refreshing, but they also taste absolutely fantastic straight from the fridge or freezer. Happy baking!
Preparation Time: 1 hour
Inactive Preparation Time: 1 1/2 hours, plus about 2 for chocolate to set
Baking Time: 10 – 12 minutes
Makes: 5 dozen
- 113 grams (8 tablespoons) unsalted butter, melt and cool slightly (15 – 30 minutes)
- 1/4 teaspoon vanilla extract
- 1/4 teaspoon peppermint oil
- 30 grams (1/4 cup) millet flour, plus more for rolling
- 30 grams (1/4 cup) garbanzo fava flour
- 24 grams (2 tablespoons) potato starch
- 16 grams (2 tablespoons) arrowroot starch
- 1/2 teaspoon xanthan gum
- 60 grams (1/2 cup) powdered sugar
- 10 grams (2 tablespoons) Dutch-process cocoa powder¹
- 14 grams (2 tablespoons) black onyx cocoa powder
- 1/4 teaspoon Kosher salt
Make and chill dough:
Combine melted and cooled butter, vanilla extract and peppermint oil in whatever vessel you used to melt the butter (saucepan, measuring cup); set aside.
Sift millet flour through black cocoa powder into a medium mixing bowl, whisk to combine. Whisk in Kosher salt. Pour melted butter mixture into dry ingredients and stir by hand until the dough comes together into a smooth ball.
Turn dough out onto a sheet of plastic wrap, pat into about a 3/4″ thick disk, wrap tightly and refrigerate for about 30 minutes (dough won’t be rock hard, just firmed slightly).
Roll dough and cutout cookies:
Line a small, rimmed sheet pan or freezer-safe platter with a silicone baking mat or a piece of plastic wrap (make sure it’s smooth, no wrinkles); set aside.
Sprinkle rolling surface with millet flour, turn chilled dough out and knead it a few times to warm dough slightly. Use more flour on the rolling surface and sprinkled on top of the dough as needed. Working with half of the dough at a time, roll out until 1/8″ thick (see notes in the next paragraph for rolling tips).
There’s no need to do the whole, one roll, turn dough 45°, roll, turn, roll, turn, on and on as with pie dough. It’s really better if you don’t try to do that past the first couple rolls — the dough is a bit too delicate and crumbly and just tends to tear. Let it stick to the rolling surface, just be aware of it sticking to the rolling pin and sprinkle more flour on top as needed. And if it’s giving you too much trouble, just scrape it up, knead again until it’s a ball and try again — probably with a little more flour on the counter and top of the dough this time. You cannot ruin this dough.
Use a small, round cookie cutter (about 1 1/2″) to cut out cookies. Transfer to the prepared sheet pan using a small or large offset spatula (you really need a very thin tool to get under the cookies). No need to leave any space in between cookies — we’re not baking them yet.
Repeat rolling/cutting/arranging with other half of dough, knead together scraps and re-roll/cut until it’s all shaped. If you run out of space on your baking sheet, line another (or a plate) with plastic wrap — do not stack cookies! Transfer baking sheet(s) to the freezer and chill for 1 hour.
Bake and cool cookies:
While cookies chill, arrange oven rack in the center and preheat oven to 350°F. Line two large, rimmed baking sheets with silicone baking mats or parchment paper; set aside.
Once cookies have chilled for an hour, arrange about half on one of the prepared sheet pans — they hardly spread, so about 1/2″ of space between each is enough. Return other half of cookies to the freezer. Bake until edges are firm but middle is still a little soft, about 10 – 12 minutes (I baked mine for 12). Remove from oven and allow cookies to cool on the baking sheet for about 2 minutes before removing to a cooling rack.
Repeat with the second prepared cookie sheet and other half of the cookies from the freezer. (Please note: it’s really important that you don’t use the cookie sheet that just came out of the oven, it will cause the cookies to warm, spread and generally not come out as well. If you only have one sheet pan or baking mat that’s ok — just let it cool to room temperature before using it.)
Melt chocolate and coat cookies:
Line a large, rimmed sheet pan with a sheet of wax paper; set aside.
Ok, what we’re really doing here is tempering the chocolate, but it’s really not scary — I take a very relaxed approach (read: no thermometers), and melt the chocolate in batches. The worst that can happen is that once cooled the chocolate looks marbled; while probably not desirable, it is a pretty cool-looking effect. If you want to do things by the book, please refer to the instructions here or here or consult with the chocolate manufacturer for their recommended method.
In a small, heatproof bowl (preferably metal, I use a 2-quart stainless steel one by Endurance/RSVP) or the top of a double boiler, combine 5 ounces of the chocolate with 5 drops/dashes peppermint oil. In a small saucepan (I use this 2-quart pan) over medium heat, warm about 1” of water (make sure there’s at least 1/2” of space between the water and bottom of the bowl when it’s placed over the top) until it just barely reaches a simmer. Reduce heat to low and set bowl with chocolate over top. Stir/fold chocolate and heat just until about 75% of the chocolate is melted. Remove bowl from heat and slowly stir until smooth.
Place one cooled wafer into the chocolate. Using a fork, drizzle chocolate over top to cover completely. Scoop cookie out of chocolate with the tines of the fork (don’t let it sneak up to the curved part of the fork, that can cause it to break); holding cookie over bowl of chocolate, tap fork handle on the side of the bowl a few times to remove excess chocolate, letting it drip through the tines (this also pops most air bubbles and ensures a thin, smooth coat). Scrape bottom of fork against the edge of the bowl and slide cookie off fork, onto the prepared pan. Repeat with the remaining cookies, melting other half of the chocolate when needed (no need to wash out the bowl between chocolate batches).
Allow cookies to set at room temperature for about 1 hour before placing in the fridge. Chill until chocolate is set (about 1 hour) before serving or packaging. They keep best stored in the fridge or freezer.
¹ I use Droste cocoa powder. It can be a bit difficult to track down, but is available on Amazon or at upscale grocers (Drager’s Markets in the Bay Area and occasionally Whole Foods). The most important thing is that you use a Dutch-process (alkalized) cocoa powder for this recipe, not a natural cocoa powder such as this one by Hershey’s. I haven’t tried the Dutched cocoa powder sold through Savory Spice Shop, but it may be worth a go if you’re already at the store or need to order the black cocoa though them.