Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.

Melt the butter in a medium sauté pan over medium heat, stirring constantly until it turns light amber (5-7 minutes).

Combine the cooled brown butter with granulated sugar and light brown sugar in a large mixing bowl and beat for about 2 minutes until smooth.

Mix in the baking soda, eggs, and vanilla extract, and beat until well combined (about 30 seconds).

Gradually add the all-purpose flour while mixing on low speed, scraping down the bowl's sides as needed.

Fold in the dark chocolate chips gently without overmixing.

Form balls of dough using a cookie scoop or about 1 ½ tablespoons of dough and place on the prepared baking sheets.

Bake for 12-15 minutes or until edges are golden and centers are soft.

Let cool on the sheets for a few minutes, then sprinkle with flaky sea salt.

Transfer cookies to a wire rack to cool completely before serving.