2 1/2 cups all-purpose flour
1 teaspoon cornstarch
1 teaspoon baking soda
1/2 teaspoon salt
1 cup (2 sticks) unsalted butter, room temperature
1/2 cup sugar
1 cup brown sugar
2 large eggs
1 1/2 teaspoons vanilla extract
1 1/2 cups pecans, roughly chopped, toasted
Sea salt, optional
Place pecans in a pan or skillet over medium heat and toast on the stove, stirring occasionally, for 5-10 minutes, or until fragrant, but not burned.
In a medium bowl, whisk together flour, cornstarch, baking soda and salt.
In a large bowl or mixer, beat butter for 1-2 minutes, or until creamy and fluffy. Add in both white and brown sugar and beat for 2-3 minutes, or until lightened in color.
One at a time, beat in eggs, waiting until each is incorporated before adding the next, then mix in vanilla extract.
Gradually mix dry ingredients into wet ingredients, making sure to not overmix, then fold in toasted pecans.
Wrap cookie dough tightly in plastic wrap and refrigerate for 2-3 hours, or for up to 3 days. Remove from fridge and let sit at room temperature for 15-20 minutes.
Preheat oven to 350º F and line 2 baking sheets with parchment paper.
Use a spoon or small scooper to scoop 1 tablespoon of dough and roll into balls. Place on cookie sheet(s) and repeat with remaining dough. Sprinkle tops of dough with flaky sea salt, if using.
Place baking sheets in oven and bake for 11-12 minutes, or until edges are lightly browned. Remove from oven, centers will be soft, and let cool 5 minutes on baking sheet before transferring to wire racks.