How to make
Dissolve the sugar in the hot, strong espresso. Mix well with the butter and vegetable oil and leave the mixture to cool. Add the liqueur and essence to it. Separately, mix the cocoa, whole wheat flour, baking powder and cinnamon. Mix the liquid and dry ingredients together.
From the resulting homogeneous mixture, shape balls and flatten them slightly. Arrange them on a greased baking tray with baking paper. Put them to bake in moderate preheated oven until they release their flavor.
Optionally, while still warm, roll them and press in some chopped nuts (walnuts, almonds, peanuts).