In a bowl sift flour and baking powder, add salt and cocoa powder.
In a separate bowl, beat softened butter (with a whisk) with sugar to a creamy state.
In the oil mass, add the egg and vanilla. Stir well.
Pour the milk.
Pour the flour + cocoa and gently, spoon, knead the soft dough.
Lay the baking sheet with baking paper. Tablespoon spread round "down the hill" test. Between them should be enough space for further "growth"))) Oven should be heated to 200C. Send it cookies for 15 minutes, so that it has increased in size.
Marshmallow cut into pieces along and across as a hungry soul wishes)) Spread one piece of marshmallow on each cookie, slightly pressing the marshmallow to the liver.
Return to the oven for 3-5 minutes.
In General, melt the chocolate and pour on top of the cooled cookies - "fatter and thicker".