Start by placing your unsalted butter in a saucepan over medium heat. Stir it occasionally as it melts. Continue cooking until the butter turns a golden brown color and develops a nutty aroma. This should take about 5-7 minutes. Be careful not to burn it! Once browned, remove it from the heat and let it cool slightly.
In a large mixing bowl, combine the browned butter, light brown sugar, and granulated sugar. Use a hand mixer or stand mixer to cream the mixture until it’s light and fluffy—about 2-3 minutes.
Add the eggs, egg yolk, and vanilla extract to the sugar mixture. Beat until well combined.
In a separate bowl, whisk together the all-purpose flour, baking soda, baking powder, and salt. Gradually add this to the wet ingredients, mixing until just combined.
Gently fold in the semi-sweet chocolate chips and chocolate chunks using a rubber spatula.
For the best flavor and texture, cover the dough and chill it in the refrigerator for at least 30 minutes. This step is crucial as it helps the cookies to maintain their shape while baking.
Preheat your oven to 350°F (175°C). Line your cookie sheets with parchment paper.
Once the dough has chilled, use a cookie scoop or tablespoon to drop rounded balls of dough onto the prepared cookie sheets, leaving enough space between each cookie.
Bake in the preheated oven for 10-12 minutes, or until the edges are golden and the centers are still soft.
Remove from the oven and let the cookies cool on the sheets for about 5 minutes. Sprinkle with a pinch of fine sea salt before transferring to a cooling rack to cool completely.
