Place all your ingredients into a mixer (gluten free flour, xanthan gum, caster sugar, dairy free margarine, egg and vanilla extract). Combine thoroughly. (you can do the same with a hand mixer if you prefer)
Remove from mixer and bring the dough together into a ball.
Wrap the dough in clingfilm and chill for 30 minutes.
Preheat oven to 180c (160 fan)
Grease a couple of baking sheets.
Remove the dough from the fridge and roll it out on a lightly floured surface.
Roll it out to about 1/2 cm thickness & then, using a cutter to cut out your shape - Halloween Pumpkin preferably! Place your shapes on your baking tray.
Place in the oven for around 12-15 minutes, until lightly golden.
Once slightly cooled, transfer to a cooling rack.
Whilst your biscuits are both in the oven & cooling get your icing prepared.
Roll out your icing on a surface lightly dusted with icing sugar. Make sure its fairly thin.
Cut out your shapes with both, if you have cutters/templates it might be easier!
Stick your icing to your biscuits. I lightly brush the icing with luke warm water and stick it to the biscuits. (be patient & be gentle!!)
Enjoy!
Notes
If you prefer you can stick the icing to the biscuits using either a light layer of jam OR by making a little dairy free butter cream and spreading it on the biscuits first.