These cookies are very tasty, and similar to the Girl Scout's Thin Mints.
*Edit* Oh, by the way, the cookies pictured are only half of the batch, I left the other roll in the freezer for a rainy day.
Step 1: Ingredients and Equipment
1 1/2 cups all-purpose flour
1/2 cup unsweetened cocoa powder
1 teaspoon baking powder
1/2 teaspoon salt
1 cup (2 sticks) softened butter
3/4 cup sugar
1 large egg
2 teaspoons pure vanilla extract
3/4 teaspoon peppermint extract
7 ounces bittersweet or semisweet chocolate, finely chopped
1 teaspoon vegetable oil
1/2 teaspoon peppermint extract
Large and medium mixing bowls
Measuring cups and spoons
Double-boiler (or sauce pan and bowl, either way)
Hand mixer (or stand mixer)
Wooden spoon, or something for stirring
Stoneware bar pan (this is what I used, but a baking sheet covered in parchment paper would work just as well)
Cutting board or baking sheets that will fit the refrigerator
Whisk (was absent during this photo shoot)
Step 2: Combine Dry Ingredients
Step 3: Combine Wet Ingredients
Combine the butter and sugar in a large mixing bowl. With an electric mixer, (I suppose you could use a stand mixer if you wanted, I didn't want to lug mine upstairs just for this step) beat on medium-high speed until fluffy, 2 to 3 minutes. Add the egg and the extracts and beat until smooth. Stir in the flour mixture with a wooden spoon or other stirring utensil until just incorporated.
Step 4: Divide Dough, and Chill
Divide the dough in half. Turn one portion onto a piece of waxed paper and shape it, rolling it inside the paper, into a log about 10 inches long. Repeat with remaining dough. Roll the waxed paper completely around the logs and twist the ends to help hold it all in place. Stick the logs into the freezer for about 2 hours, or up to 24 hours, if you'll be baking the cookies another day. Any longer than a day in the freezer, and the logs need to be tightly wrapped in plastic wrap and foil, and will last up to one month. You can slice and bake directly from the freezer.
Step 5: Bake the Cookies
You can bake them at this point, but I rolled each slice into a ball and placed them on the bar pan about two inches apart. I used a small juice glass, and covered the bottom with parchment paper, secured with a rubberband. I flattened each ball with the glass, then baked in 350 degree, preheated oven for about 11 minutes, until the edges were firm.
Remove from the oven, but leave them on the baking sheet for 5 minutes, then remove them with a metal spatula to a wire rack until completely cool.
Step 6: Coat in Chocolate
Put about an inch of water in the bottom of a double-boiler or saucepan and bring to a simmer. Place the chocolate and vegetable oil in the top of the double-boiler or a stainless-steel or glass bowl big enough to rest on top of the saucepan, making sure that the water doesn't touch the bottom of the bowl. Heat, whisking occasionally, until the chocolate is completely melted. Remove from heat and whisk until smooth. Let cool for about 5 minutes, then add 1/2 teaspoon peppermint extract and combine.
If you like lots of chocolate, you can completely submerge the cookies in the chocolate (one at a time) or just dip the tops of the cookies. You could also spread the chocolate on top with an offset spatula. After you coat the cookies to your liking, place them chocolate side up on a piece of waxed paper on a cutting board (this is what I used) or baking sheets covered in waxed paper. Refrigerate for 15 minutes, or until the chocolate coating is firm.
Cookies will keep at room temperature in an airtight container for 4 to 5 days. If they last that long.