Chop walnuts coarsely and set aside.

Add softened butter into a mixing bowl.

Add icing sugar and cream butter and sugar until pale yellow.

Add plain flour and cornstarch.

Mix slowly until mixture comes together.

Add chopped walnuts and mix evenly.

Line a U shaped cookie mould with baking paper

Gather dough together and form into a ball.

Take out some dough and fill up the lined mould..

Press dough in tightly and wrap it with the baking paper.

Remove the wrapped dough from the mould and chill it in the fridge for at least an hour.

Remove dough from the fridge, unwrap and slice about ⅛ to ¼ inch thick pieces.

Arrange pieces on a baking tray lined with baking paper.

Bake in a preheated oven at 160C until lightly brown. About 15 to 20 mins for ¼-inch thick cookies. About 10 to 15 mins for ⅛-inch thick cookies.

Remove the tray from the oven and cool on a cooling rack.