Set strong coffee, pour in a bowl and let cool.
Put the butter, the snuff of salt, the vanillaerger, the yolk and the flower sugar in a large bowl and beat nicely light for 5 minutes.
Take a cake holder, a board with aluminum foil or a flat plate.
Take 4 cookies and each stick them with some cream, apart, stuck on the plateau, you choose whether you want to make individual, square or rectangular shape.
Put the cream in a piping bag with a fine star spraying, or you spread with a butter mesh.
Spray a thin layer on the 4 cookies.
Drenk cookie per cookie in the coffee and carefully press the cream.
Repeat until the cookies are on.
Finish at the top with some dots of cream and finish with sprinkles and cocoa powder.