In a saucepan, melt 3 tablespoons of unsalted butter over medium heat. Add the chopped pecan halves and toast for 3–4 minutes until fragrant and golden brown. In a separate pan, melt 2 sticks of unsalted butter over low heat until deep amber, about 5–7 minutes. Let cool slightly.

In a medium bowl, whisk together the flour, cornstarch, salt, cinnamon, and baking soda. Set aside.

In a large mixing bowl, combine the cooled browned butter with dark brown sugar and granulated sugar. Beat until smooth and creamy, then add vanilla extract and eggs, whisking until mixed.

Gradually mix in the dry ingredients until just combined. Do not overmix.

Fold in the toasted pecans gently with a spatula.

Cover with plastic wrap and refrigerate for 1–2 hours.

Preheat oven to 375°F (190°C) and line baking sheets with parchment paper. Scoop tablespoon-sized balls of dough onto sheets, spaced 2 inches apart. Bake for 9–12 minutes until edges are golden and centers soft.

Let cookies sit on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely. Optionally, top with additional pecans while warm.