Preheat your oven to 180°c (160°c for a fan assisted oven) or Gas Mark 3 and grease a couple of baking trays with a little butter.
Cream together the butter & sugar in a large bowl until it becomes light & fluffy.
Sift in your flour & cornflour and mix to form a stiff dough. Tip the dough onto a floured worktop and gently knead until smooth.
Roll your dough to around 1cm thick and cut into your desired shapes. Transfer each shortbread to your pre-greased baking trays and prick each one with a fork on top.
Bake in your pre-heated oven for around 15-20 minutes until the edges of the shortbread are golden.
Remove from the oven and sprinkle a little sugar over each shortbread. Leave to cool on their tray for around 10 minutes before transferring to a wire rack to cool completely.
