In a large bowl, sift together flour, cocoa and sugar then, using a fork, make a well in the center and add all the other ingredients (+ milk if needed), blending everything with your hands to form a thick dough.
Gather the dough into a ball, wrap the ball in cling film and refrigerate until firm, at least 30 mins; in the meantime, preheat the oven to 350 F.
Roll out the dough on a floured surface or between two sheets of wax paper and cut out the cookies with the cookie cutters of your choice.
Nicely arrange the cookies on a baking pan lined with wax paper then transfer the pan inside the oven.
Bake the cookies for 10/15 mins, until they're easily removed from the wax paper surface.
Eat the cookies straight away or store them in a tin box.