Preheat the oven to 350 degrees. Line a baking sheet with parchment paper or silpat liner.
Beat together the butter and brown sugar until creamy. Beat in the eggs and vanilla.
In a separate bowl, stir together pastry flour, cocoa powder, baking soda, instant coffee granules, and salt.
Mix the dry ingredients into the butter and sugar mixture.
Stir in chocolate chips.
Put the powdered sugar in a small bowl.
Use your hands to form the dough into small balls. Roll the balls through the powdered sugar until the outside is completely covered. Place on cookie sheet and bake for 10 minutes, or until the tops of the cookies begin to crack.
Cool for 5 minutes on the pan before transferring to a wire rack.
Store in an airtight container.
Notes
These cookies don't spread very much, so if you prefer a less puffy cookie, press down lightly on the tops before baking.
Recipe by the ringers at https://www.theringers.co/2014/12/fudgy-mocha-cookies/