SALTED Butter - room temperature (see note 1) • icing sugar (see note 2) • vanilla extract (OPTIONAL) • potato flour • milk powder • plain flour • fine salt (OPTIONAL - our daughter always adds salt as she likes her cookies taste slightly salty) • cornflakes - coarsely crushed • . Butter should be at a cool room temperature, so it's soft enough to mix with sugar and other ingredients • . Icing sugar is also known as powdered sugar or confectioners' sugar. It creates a soft, tender, melt-in-your-mouth texture cookies • . You should not pack your measurement cup when measuring flour because it compacts the flour, leading to an inaccurate measurement that is often too much and can result in dry and dense baked goods