Chop two-thirds of the pistachio nuts. Knead the marzipan with the chopped nuts and alittle orange blossom water. Roll into 20 balls with your hands dusted with icing sugar. Carefully pit the dates and fill them with the marzipan balls. Press a whole pistachio nut on each date and serve them, preferably in one of those beautiful tiny paper cups, if you can lay your hands on them.