The ingredients for the cookies.

Softened butter, beat with sugar.

Add the egg and vanilla sugar and whisk well.

Add 2 stack. flour, then divide the dough into 2 parts, one add cocoa powder. Then mixed into each part of the flour until until the dough longer sticks to hands.

Formed dough balls and send for an hour in the fridge, pre-wrapped the dough in plastic wrap. Divide each part in half. One of them left on the table, and the second again in the fridge.

Whisk milk with egg yolk.

Roll out white dough into a rectangle 1 cm thick and cut into cubes of the same width - 1 cm to do the same with chocolate dough.

Then, brushing flanks are whipped and mixed with milk, egg yolk, put the cubes in a checkerboard pattern (in 3 rows and 3 "floors").

Take out of the refrigerator the deferred part of the dough and roll out, the dimensions of the rectangle should be 12 X 21 cm and a thickness of approximately 0.5 cm Length can vary, but a width of 12 cm - standard! Lubricates the rectangles with the egg yolk with milk and tucking into his cooked chess bars. Again put it in a refrigerator for half an hour to cool. Preheat the oven to 160 C. Lay a parchment baking sheet, cut into cookie slices with a thickness of 7 mm and bake for 15 min until tender, but not allowing to brown, otherwise lost a checkerboard effect.

Brew tea and call to the table! Bon appetit!