Line 2 sheet pans with parchment paper (note: these cookies spread out quite a bit, so you’ll likely need to bake them in batches).
In a medium-sized bowl, whisk together the flour, cocoa powder, baking powder and salt.
In a stand mixer fitted with the paddle attachment (or using an electric mixer), cream the butter and sugar together on medium-high speed for several minutes until light and fluffy. Scrape down the bowl. Add the eggs, peppermint and vanilla extracts. Scrape down the bowl once again to ensure the ingredients are evenly combined.
Add the dry mixture in several batches on low speed until evenly combined. Stir in the chopped mints.
Use a 2-tablespoon scoop to portion out the dough onto the prepared baking sheet. Press the cookies down to about 1 inch thick, keeping the cookies about 2 inches apart (see notes).
Chill the cookie dough for 15 minutes. Meanwhile, preheat the oven to 350 degrees F.
Bake the cookies for 9 to 12 minutes (9 for soft, 12 for slightly crunchy).
Cool for 5 minutes, then transfer to a wire rack to finish cooling.
My trick for chilling cookies is actually to scoop them relatively close together (but not touching), so that I can chill the entire batch on one sheet pan. After they’ve chilled, I portion them out onto a separate sheet pan spread out appropriately for baking while the remaining cookies stay in the refrigerator. This allows all of the cookies to chill on one sheet pan, even if they require baking in several batches.I'm sure you can swap in other chocolate mints for the Andes Mints, but I can't promise identical results.Adapted from Duff Goldman