Instructions:

• Brown the Butter: In a light-colored saucepan or skillet, melt the butter over medium heat. Continue cooking, stirring constantly with a heat-proof spatula, scraping the bottom of the pan. The butter will melt, then foam, then eventually turn a beautiful golden-brown color with nutty brown bits at the bottom. This usually takes 5-8 minutes. As soon as it reaches a rich amber color and smells nutty, remove from heat and immediately pour the brown butter, along with all the browned bits, into a large heatproof mixing bowl. Let it cool for 15-20 minutes, or until it's no longer hot to the touch but still liquid.

• Combine Sugars & Wet Ingredients: Add the granulated sugar and brown sugar to the cooled brown butter. Whisk vigorously for 1-2 minutes until smooth and glossy. Add the whole egg, egg yolk, and vanilla extract. Whisk again for another 1-2 minutes until the mixture is lightened in color and creamy.

• Mix Dry Ingredients: In a separate medium bowl, whisk together the all-purpose flour, baking soda, and salt.

• Combine Wet & Dry: Gradually add the dry ingredients to the wet ingredients in two additions, mixing on low speed (if using a mixer) or with a spatula until just combined. Be careful not to overmix, as this can lead to tough cookies.

• Add Chocolate: Gently fold in the chocolate chips or chunks until evenly distributed throughout the dough.

• Chill Dough (Recommended): For best results and chewier cookies, cover the dough and refrigerate for at least 30 minutes, or up to 24 hours. Chilling allows the flavors to meld and prevents excessive spreading.

• Preheat Oven & Prep Pans: Preheat your oven to 375°F (190°C). Line two large baking sheets with parchment paper or silicone baking mats.

• Scoop & Bake: Scoop rounded balls of dough (about 2 tablespoons each) and place them about 2 inches apart on the prepared baking sheets. If desired, lightly press a few extra chocolate chips onto the tops of the dough balls for a prettier finish.

• Bake: Bake for 10-12 minutes, or until the edges are golden brown and slightly crispy, and the centers are still soft and slightly underbaked (they will continue to set as they cool).

• Cool & Serve: Remove the baking sheets from the oven. If desired, immediately sprinkle the warm cookies with flaky sea salt. Let the cookies cool on the baking sheets for 5-10 minutes before transferring them to a wire rack to cool completely. Enjoy!