Sift together all dry ingredients except the coffee powder and salt.
In a separate bowl, beat together all wet ingredients, plus the coffee and salt. Make sure they are thoroughly combined.
Make a well in the dry ingredients and pour the wet ingredients into the dry. With either a paddle attachment or a silicone spoon, stir together until a dough is formed, and all the dry ingredients are thoroughly mixed in.
Cover with cling wrap and put in the fridge for four hours to overnight.
Prepare a bowl filled with the icing sugar. Using a small spoon, or rolling out the dough into logs, make 1 inch balls of dough (or 2 inch balls.)
Roll the dough balls in icing sugar and place on a lined baking tray, about 2 inches apart.
Bake in a preheated oven at 180 degrees centigrade / 350 degrees F, for 10 to 12 minutes. Do not overbake, or you lose the chewy texture of the cookies! (For 2 inch balls, about 15 minutes.)
Cool for about 10 minutes on tray before removing. Cookies should be a somewhat cakey texture, chewy, but not falling apart. Excellent slightly warm, or with tea or coffee.