Chop the chocolate coarsely and melt with the butter over a warm water bath. Set aside and let cool.

Stir sugar, salt, egg and yolk in the chocolate mixture.

Sift flour, cocoa, baking soda and cinnamon on top and stir everything into a dough.

Cover the dough with foil and place a minimum of 2 hours in the refrigerator.

Using a spoon to parting about 30 equal pieces from the dough and roll into balls. Roll the balls then in icing sugar and spread on a lined baking sheet.

Bake in preheated oven at 175°C for about 12 minutes. Remove and let cool.