2. Whisk together flour, cocoa powder, baking powder and salt in a separate bowl. Slowly pour the flour mixture into the sugar mixture and stir until well combined. Chill the dough in the refrigerator for 15 to 30 minutes.
4. Place cookies onto a baking sheet lined with parchment paper. Bake 8 to 10 minutes, or until the cookies are slightly crisp around the edges and soft in the middle. Allow to cool on the pan for 2 minutes, and then transfer to a cooling rack.