Preheat the oven to 350°F (175°C). Line a baking sheet with parchment paper.
In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy, about 3-4 minutes using an electric mixer.
Mix in the vanilla extract.
In a separate bowl, whisk together the all-purpose flour, cornstarch, and salt.
Gradually add the dry ingredients to the butter mixture, mixing until just combined.
Fold in the toasted pecans using a rubber spatula.
Divide the dough into two portions and shape each portion into a log about 1.5 inches in diameter. Wrap in plastic wrap and refrigerate for at least 30 minutes to firm up the dough.
Once the dough is chilled, remove from the refrigerator and slice into ¼-inch thick rounds. Place them on the prepared baking sheet, leaving space between each cookie.
Bake in the preheated oven for 18-20 minutes, or until the edges are lightly golden.
Allow the cookies to cool on the baking sheet for a few minutes, then transfer them to a cooling rack to cool completely.