In a mixing bowl, combine the very soft unsalted butter and powdered sugar, mixing until well blended.
Gradually add the all-purpose flour and cornstarch to the mixture, stirring until a dough forms.
Once the dough is ready, shape it into small balls and place them on a baking sheet.
Bake in a preheated oven until the cookies are lightly golden, then allow them to cool before serving.
