In a saucepan over medium heat, melt the butter. Stir constantly as it foams and then turns golden brown with little brown bits on the bottom (about 5–8 mins). Once it smells nutty and toasty, remove from heat and pour into a heat-safe bowl. Let it cool for 15–20 minutes (you don’t want it piping hot).
Preheat the oven to 350°F. Line two baking sheets with parchment paper.
Once the brown butter is warm (not hot), add the dark brown sugar and granulated sugar. Mix until smooth and glossy.
Beat in the eggs and vanilla extract until fully combined—about 1 minute. The mixture should look creamy and thick.
Add flour, baking soda, and salt. Mix until just combined—don’t overwork the dough.
Fold in the chopped chocolate
Allow the dough to chill for at least an hour or overnight.
Scoop into 2–3 tbsp balls and place on the prepared baking sheet, leaving space to spread.Bake for 10–12 minutes, until the edges are set and golden but the centers look slightly underbaked.
Let cookies cool on the sheet for 5 minutes before transferring to a wire rack. Sprinkle with flaky salt while warm if desired.
