Preheat oven to 200°C/fan 180°C/gas mark 6.
Place butter, caster sugar and Fate low protein all-purpose mix into a mixing bowl.
Rub butter into the flour and sugar mixture until it binds together, slowly adding water whilst kneading to form a manageable dough.
Transfer to a surface lightly dusted with Fate low protein all-purpose mix, and continue to knead until smooth.
Roll dough to a thickness of ½ a centimeter, cut into 5-8 pieces (using Christmas cutters) and place onto a lightly greased baking tray.
Cook for 20-25 mins, until golden in colour.
Remove from oven and cool on wire rack for 30 minutes.
Decorate with icing and edible glitter then serve.
Fate low protein all-purpose mix is a food for special medical purposes and must only be used under medical supervision.