It is an obvious fact that the recipe for a simple COOKIE should be tried by everyone. Interesting 

Recipe for cookies with cracks (marble),
the recipe is designed for a double portion:
Soft butter - 200 g
Sugar-320g
Vanilla sugar - 20 g
eggs - 5 pcs
A pinch of salt
Baking powder for dough - 2 tsp.
cocoa-100 g
flour-300 g
chocolate - 2 bars as desired
powdered sugar