Take 220g (2 cups) of coca powder (make sure you take as finer powder you can find, look at the picture) and put them in a bowl. Take 160g (3/4 of a cup) of butter and put them in bowl containing the cocoa powder. Using a spoon grind bigger pieces of cocoa powder. I recommend chopping the butter in smaller pieces for easier processing. Put the contents of the bowl in a blender or a food processor and blend them into a fine paste (check the last picture), if you don't have an access to a blender or a food processor you can use a regular mixer for the job but I will warn you, it will be messy.