Over a sheet of parchment paper, sift flour, baking powder, cocoa powder, instant coffee, kosher salt and set aside.
In a mixing bowl, add vegetable oil, sugar, mint extract, vanilla extract and use a whisk (or mixer) to combine. Add in the eggs. Lift up the parchment paper of dry ingredients and funnel it into the mixture. If you are using a mixer funnel dry ingredients slowly with mixer set on low speed. Mix until just combined. Chill the dough for 3 hours.
Preheat your oven to 375ºF. Using a 1 ounce scoop (#30 disher), scoop the dough onto a baking sheet lined with parchment paper. This recipe should yield about 12 to 15 scoops.
Bake for 12 minutes. Remove from baking sheet and allow them to cool for about 15 minutes before serving.