01 - Preheat oven to 350°F (175°C) and line two baking sheets with parchment paper.
02 - Cream softened butter with powdered sugar in a large bowl using an electric mixer until light and fluffy, about 2 minutes.
03 - Sift together all-purpose flour, cornstarch, and salt. Gradually add to the butter mixture, stirring until a soft dough forms.
04 - Roll tablespoonfuls of dough into balls and arrange spaced 2 inches apart on prepared baking sheets.
05 - Bake for 12 to 15 minutes, until the edges are just pale golden. Do not overbake.
06 - Remove cookies from oven and allow to cool on the baking sheets for 5 minutes. Gently dust cooled cookies with powdered sugar before serving.