Closely adapted from Serious Eats. Serious Eats suggested dusting with a combination of powdered sugar and ancho chile powder, which my family loved. I however preferred the raunchier flaky sea salt, coarse Aleppo chile pepper and sanding sugar combination. Be aware that the salt intensifies the chile kick.
In a medium bowl, whisk together cocoa powder, flour, salt, and both chili powders.
In a large bowl of a stand mixer (or using a handheld), beat together butter and sugar until light and fluffy on medium speed, about 4 minutes. Mix in eggs one at a time and beat for another minute.
Beat in vanilla and caffe sport extract (or coffee extract or instant espresso powder).
Mix in flour mixture in 3 additions, and then beat on medium speed for about 2 minutes, until dough has become smooth and cohesive.
Split dough in two equal parts. Roll each half into a 1 1/2 inch wide log. Wrap each log in plastic wrap. Let dough chill in refrigerator for at least 1 hour.
When you are ready to bake, preheat the oven to 350 F. Line 2 baking sheets with parchment paper.
If desired, sprinkle the unbaked coins with flaky sea salt, coarse Aleppo chile pepper and sanding sugar.
Bake until evenly lightened in color but still chewy in texture, about 15 minutes.
If desired, let un-garnished cookies cool before dusting with confectioners sugar and extra ancho chili powder.