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

Melt the butter in a saucepan over medium heat until it turns a rich golden brown and smells nutty. Be careful not to burn it. Pour into a large heatproof bowl and let cool slightly for about 5-10 minutes.

Add the dark brown sugar and granulated sugar to the browned butter. Whisk until smooth and well combined.

Beat in the vanilla extract. Then, add the eggs one at a time, whisking vigorously after each addition until fully incorporated.

Gradually add the dry ingredients to the wet ingredients, mixing on low speed or by hand until just combined. Do not overmix.

Gently fold in the chocolate chunks and nuts (if using).

Cover the dough and refrigerate for at least 1 hour (or up to 2 days) to allow the flavors to meld and prevent excessive spreading.

Preheat your oven to 191 °C (190 °C). Line baking sheets with parchment paper.

Scoop rounded tablespoons of dough onto the prepared baking sheets, leaving about 2 inches between each cookie.

Bake for 9-12 minutes, or until the edges are golden brown and the centers are still slightly soft. The cookies will continue to set as they cool.

Let the cookies cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.