Preheat oven to 180 degrees C (350 degrees F). Grease cookie trays.
Cream the butter margarine or shortening, caster sugar, eggs and vanilla.
In a separate bowl, stir the flour, 2/3 cup cocoa, baking powder, bicarbonate of soda, salt and spices. Add flour mixture to butter mixture. If too sticky add more flour, if too dry add a little milk. Add nuts and mix with hands. Must be of consistency to roll into little 1.5-2.5cm balls.
After you have cookie dough to handling consistency by adjusting it with either the flour or milk, roll into little balls, place on the cookie tray and bake for about 10-12 minutes, cookie should be firm. Do not overcook. Remove from oven, let rest on the tray for a few moments and remove to wax paper. When cool, frost with icing sugar and cocoa glaze.
To Make Glaze: Combine 4 cups icing sugar, 1/4 cup cocoa, add about 1/2 cup milk. Consistency should be of a glaze. Pour small amount of glaze over each cookie (about 1 tsp.). Decorate with sprinkles while glaze is still wet.