Preheat your oven to 175°C ( 350°F).
Line a baking pan with parchment paper or silmat.
Sift the icing sugar into a mixing bowl.
Add the butter and mix together using a paddle attachment until mixture is smooth and creamy. If you don’t have a stand mixer you can use a hand mixer or food processor.
Add the all purpose flour into the butter mixture and mix until dough begins to form.
Transfer the cookie dough onto a floured working surface and roll it into a 2 inch log in width.
Cover the the shortbread dough with plastic and refrigerate for 1 hour or until dough is firm.
Remove the cookie dough from the fridge and cut into 1/2 inch thick round discs.
Place cut cookie dough discs onto baking tray separating them anout 1/2 inch apart from each other.
Bake fir approximately 15-18 minutes or until the butter cookies are light golden color.
Cool butter shortbread cookies onto wire rack for 20 minutes before serving.
Store cookies in an air tight container.