Brown Pecans & Butter: Melt 3 tablespoons of unsalted butter in a skillet over medium heat. Add pecan halves and stir until fragrant and golden, about 3-5 minutes. Set aside to cool. In another saucepan, brown 2 sticks of unsalted butter until deep amber and nutty, about 8-10 minutes. Cool slightly.

Combine Dry Ingredients: Whisk together 2 cups of all-purpose flour, 1 tablespoon of cornstarch, ½ teaspoon of salt, ½ teaspoon of cinnamon, and ½ teaspoon of baking soda in a medium bowl until well combined. Set aside.

Combine Wet Ingredients: Whisk the cooled browned butter with 1 cup of dark brown sugar and ½ cup of granulated sugar until smooth. Add 1 tablespoon of vanilla extract and 2 large eggs plus 1 yolk, beating until creamy.

Mix Dough: Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined. Avoid overmixing.

Fold in Pecans: Gently fold in the cooled, toasted pecans with a spatula until evenly distributed. Chill the dough for at least 1-2 hours.

Chill Dough: Cover the dough with plastic wrap and refrigerate for at least 1-2 hours or up to 24 hours.

Bake Cookies: Preheat oven to 375°F. Scoop dough onto prepared baking sheets, spacing at least 2 inches apart. Bake for 9-12 minutes until edges are golden.

Cool Cookies: Allow cookies to cool on baking sheets for 5 minutes before transferring to a wire rack. Optionally top with an additional pecan half.