Preheat oven to 160°C (fan bake). In a mixing bowl beat the butter and icing sugar together until light and fluffy. Sift flour, cornflour, Gregg's Ground Ginger and Gregg's Ground Cardamom into the creamed mixture and mix to combine.
Roll into 24 small balls and place on a baking tray lined with baking paper. Press dough with a fork to gently flatten.
Bake for 15-20 minutes until cooked. Biscuits will be pale but base will be a light golden colour. Leave on the tray for 5 minutes before transferring to a baking rack to cool completely. When cold fill with orange buttercream.
Beat together butter, orange zest and icing sugar. Add orange juice to make it a spreadable consistency. Spread one half of the biscuits with the orange cream and join together with remaining biscuits.