In a bowl, whisk together flours, baking soda, salt, espresso powder, and cocoa powder.
In the bowl of a stand mixer with paddle attachment, beat butter for one minute on medium speed (speed 4 of Kitchenaid). Scrape down sides and add sugar, beat for two minutes to properly cream the butter and sugar, until light and fluffy. Periodically stop the mixer and scrape down sides.
Add egg and vanilla, mix until mostly combined, then add dry mixture and mix for 1 minute, until combined and no dry streaks of flour are left.
Preheat oven to 350 degrees F. The dough will rest on counter during this time, covered.* When oven is preheated, scoop 40 gram dough balls onto parchment lined baking sheet. Bake for 10 to 11 minutes, until tops are set. Do not overbake. Remove from oven and bang pan once on the countertop (or oven top), which will flatten the tops of the cookies slightly and give a little ripple to the edges.
Lightly press an andes mint into the center of each cookie. Wait about two minutes and it will be melted, swirl chocolate at this point. Let fully cool. Enjoy!
Cookies can be stored in covered container on counter for 4 to 5 days. You can also freeze the dough and bake anytime within 3 weeks.