Cream softened butter and sugar together until smooth and pale, ensuring the mixture is well combined but not overly whipped for the right texture.
Add vanilla extract, then gradually mix in flour, salt, and cornstarch until a soft dough forms that holds together when pressed.
Shape the dough into a log or disc, wrap it tightly, and chill in the refrigerator to firm up the butter and improve structure.
Slice or roll out the chilled dough into even portions, placing them on a lined baking tray with space between each piece.
Bake at 325°F (160°C) until edges are lightly golden while keeping centers pale for the perfect shortbread texture.
Allow cookies to cool slightly on the tray before transferring to a rack so they can set and achieve a crisp finish.
