Use 2 baking trays; line with baking paper. Knead the butter and marzipan paste together until smooth. Add sugar, salt, bitter almond oil, egg and flaked almonds and stir in.
Sift flour over the mixture and knead ingredients into a dough. Shape into 2 cylinders each about 4 cm in diameter; wrap in cling wrap and chill for 2 hours.
Preheat oven to 180°C. Cut cylinders into slices 5 mm thick and place on trays. Bake 10–15 minutes per tray. Mix icing sugar, egg white and liqueur to a thick icing. Ice cookies and decorate with glacé cherries and pistachio nuts.