My ingredients for the cookie base:
2 cups + 2 tbsps of flour (I used whole wheat flour)
1/4 cup tapioca flour (starch could be a possible alternative if you can't find it)
1/4 cup + 2 tbsps of cocoa (Dutch processed "for-real" cocoa)
1 cup sugar (I used raw sugar)
1/4 tsp salt
1/2 tsp vanilla sugar (extract of course can also be used)
1/2 tsp baking soda (sodium bicarbonate)
1/2 cup of butter
1/3 cup of milk
1 tsp of peppermint extract or 1/2 tsp of peppermint oil
So, how do you make the dough?
I first whisked all the dry ingredients together (flour, tapioca flour, cocoa, sugar, salt, baking soda, vanilla). Then, I added the cold butter to the dough by breaking off pieces of the solid block with my fingers. I combined the butter and the dry ingredients by hand and got a crumbly mixture that doesn't really stick together.
I then added the milk, egg, and peppermint extract. I used a hand mixer with dough hooks to combine the final ingredients and I worked the dough with my hands until it came together and turned a nice rich brown color. If your dough is still really crumbly, add an extra tbsp of milk.
Next split the dough in half and roll each half into a ball and then work the dough into two logs of minty goodness and place them onto plastic wrap. Wrap the logs and place one in the freezer and the other in the fridge. One log is for immediate baking and consumption, the one in the freezer is for your subsequent craving for more cookies.
One log makes around 24-30 cookies when sliced at a 1/4" thickness, and each log is rolled to about 2" round. The baking soda helps these cookies rise and makes them crispy, so you don't have to space them very far apart on your cookie sheet. TIP: Use dental floss to slice the dough thinly.
Bake on parchment on a cookie sheet for 12 minutes (11-13 minutes) at 375 F (190 C) depending on your oven, but our sweet spot was 12 minutes for lightly crispy cookies after completely cooling. So, let them cool completely before sampling. Also, beware of peppermint vapors when you open your oven to remove cookies, it made me cry.
Minty Chocolate outer coating
This is still a work in progress, but I used this for covering one log of cookies (~24-30 cookies):
one bar (100g) of chocolate 70% cocoa or dark baking chocolate
two drops of peppermint oil
Break up the chocolate, melt in a double boiler, add the peppermint, then dip the cookies after they are completely cooled and put them in the freezer. They actually do stay pretty well when defrosted and cooled, but some melted chocolate does get on your fingers after holding them for a bit. Make sure you don't overcook the chocolate because it will dry out!
And, I'd love to hear better solutions for the chocolate-mint outer coating!