Ingredients
120g caster sugar
175g butter
225g flour
3 tbsps cocoa powder 

Method
In a large bowl cream the butter and the sugar with a wooden spoon until completely mixed. 

Add the flour and cocoa powder and using your hands, bring together as a dough until all of the flour is mixed through the butter mixture and it is a dark chocolate colour.  Alternatively you can use a mixer with a dough hook.   

Rest for half an hour in the fridge. 

Preheat the oven to 180c. 

Cut the dough in half and place half back in the fridge.  With the half on your board, shape into a log roughly 15cm long and cut every cm.