1. Preaheat oven to 200°C.
2. Mix together flour, sugar, cocoa powder and bakin powder in a bowl.
3. Dissolve coffee granules in 1 tbsp of water and add it to the dry ingredients.
4. Add butter and egg whites and stir until it forms a dough.
5. Sift icing sugar into a bowl. Form dough balls - app. 3-4cm in diameter - and roll them in icing sugar. The dough can be sticky so coat your hands in icing sugar.
6. Place the balls on a lined baking tray, making sure there is plenty of room (4-5cm) between them.
7. Bake at 200°C for around 12 minutes until the cookies are firm to touch on the outside but still soft in the centre. Leave to cool on the tray for a few minutes before tranferring them to a cooling rack.