Mix egg yolks, sugar and vanilla sugar to a mass, slowly add butter and continue mixing. Combine the mixture with quark and stir until everything becomes homogeneous. Divide the whole mass. Mix a part of the mixture with cocoa.
Place half of the biscuits on aluminium foil (rectangle 3x4 biscuits) and spread the light-coloured mixture on top. Spread the biscuits again on this mass (3x4) and spread the dark mass. Fold the outer edges together to form a kind of small triangular "hut".
Fasten with aluminium foil and place in the refrigerator for a few hours.
Pour the chocolate icing over the hut and sprinkle the coconut shavings over it. Leave to cool further. Serve.