01 - In a small saucepan over medium heat, melt butter, stirring constantly until it turns golden brown and emits a nutty aroma, about 5–7 minutes. Brown bits will form at the bottom and you will hear crackling sounds. Transfer to a heatproof bowl and let cool for 10 minutes.
02 - Combine brown sugar and granulated sugar with the cooled brown butter. Whisk until fully incorporated, then beat in the egg and vanilla extract until the mixture is smooth.
03 - In a separate bowl, whisk together flour, baking soda, and salt. Gradually mix the dry ingredients into the wet mixture, stirring until just combined. Gently fold in the chocolate chips.
04 - Cover the dough and refrigerate for 30 minutes. This step enhances texture and prevents excessive spreading during baking.
05 - Preheat oven to 350°F. Line baking sheets with parchment paper. Scoop dough into 24 even portions, spacing them 2 inches apart. Bake for 10–12 minutes, until edges are golden and centers are slightly underbaked.
06 - Immediately sprinkle baked cookies with flaky sea salt if desired. Allow cookies to cool on baking sheets for 5 minutes before transferring to a wire rack.