Preheat your oven to 325°F (163°C) and line a baking sheet with parchment paper.

In a large mixing bowl, beat the softened butter until smooth and creamy.

Add the powdered sugar and vanilla extract, then mix until light and fluffy.

In a separate bowl, whisk together the flour, cornstarch, and salt.

Gradually add the dry ingredients to the butter mixture, mixing until a soft dough forms.

Turn the dough onto a lightly floured surface and gently knead until smooth.

Roll the dough to about ¼-inch thickness.

Cut into your desired cookie shapes using a cookie cutter or slice into rectangles.

Place the cookies about 1 inch apart on the prepared baking sheet.

Prick each cookie lightly with a fork for the traditional shortbread look.

Bake for 18–22 minutes, or until the edges are just beginning to turn light golden.

Allow the cookies to cool on the baking sheet for 5 minutes, then transfer to a cooling rack to cool completely.