Start by melting 3 tablespoons of unsalted butter in a pan over medium heat. Add the chopped pecans and cook for about 3-4 minutes, stirring frequently until they are toasted and fragrant. Remove from heat and let them cool.

In another pan, melt 2 sticks (8 oz) of unsalted butter over medium heat until it turns a light golden brown, then let it cool slightly.

In a medium mixing bowl, whisk together 2 cups of all-purpose flour, 1 tablespoon of cornstarch, 1 teaspoon of salt, 1 teaspoon of ground cinnamon, and 1 teaspoon of baking soda. Set aside.

In a large mixing bowl, whisk together the cooled browned butter, 1 cup of dark brown sugar, ¾ cup of granulated sugar, 2 teaspoons of vanilla extract, and 1 large egg plus 1 additional egg yolk until smooth.

Gradually incorporate the dry ingredients into the wet mixture, mixing on low speed until just combined.

Gently fold in the cooled, browned pecans into the dough using a spatula.

Cover the dough with plastic wrap and refrigerate for 1-2 hours; can be chilled up to 24 hours.

Preheat your oven to 375°F (190°C). Line your baking sheets with parchment paper. Portion out the chilled dough and place it on the sheets, spacing them about 2 inches apart.

Bake for 9-12 minutes, until the edges are golden brown and the centers are still soft. Allow to cool on baking sheets for 5 minutes before transferring to a wire rack.