In a medium skillet over medium heat, melt 3 tablespoons of unsalted butter. Add 1 1/4 cups of finely chopped pecans, stirring frequently for about 4-5 minutes until fragrant and lightly toasted. Remove from heat and let cool. In a separate saucepan, melt 2 sticks of unsalted butter over low heat, allowing it to brown gently for about 5-7 minutes. Once browned, set aside to cool slightly.

In a large mixing bowl, whisk together 2 1/2 cups of all-purpose flour, 1 tablespoon of cornstarch, 3/4 teaspoon of salt, 1/2 teaspoon of ground cinnamon, and 1 teaspoon of baking soda. Mix until evenly combined.

In another bowl, whisk together the cooled browned butter, 1 cup of packed dark brown sugar, 1/2 cup of granulated sugar, 1 tablespoon of vanilla extract, 2 large eggs, and 1 extra egg yolk at room temperature. Mix until smooth.

Gradually add the dry ingredients into the wet mixture, mixing on low speed until just combined. Use a rubber spatula to scrape down the sides as needed.

Gently fold the cooled toasted pecans into the dough. Avoid overworking the dough.

Cover the mixing bowl with plastic wrap and refrigerate the dough for at least 1-2 hours, or up to 24 hours.

Preheat your oven to 375°F (190°C). Line two baking sheets with parchment paper. Scoop 1.5 to 2 tablespoons of dough and place them 2 inches apart on the sheets. Bake for 9-12 minutes.

Allow the cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack. Decorate with a pecan half if desired.