Cream butter and sugar until light and fluffy, then add the flour and mix to combine. Try not to over mix – the dough will be crumbly.
Roll dough into a log and wrap tightly in cling film and refrigerate for 2 hours.
When ready to bake, remove the dough from the fridge, unwrap and slice into 1cm discs
Line the air fryer basket with baking paper leaving a 1.5 cm border free of paper to allow air to circulate, and place the biscuits inside (you may need to work in batches)
Select Bake and set the temperature to 166°C and time to 9 minutes and press start.
Ignore when prompted to add food as the biscuits will already be inside. When the cooking program has finished, let the biscuits cool slightly in the air fryer for a few minutes, before transferring to a cooling rack to dust with icing sugar, then leave to cool completely.