Start by browning the butter in a medium saucepan over medium heat. Stir often as the butter melts, foams, and finally turns a deep golden color with a nutty aroma. This step enhances the cookies with a rich, caramel-like flavor you can’t get from regular melted butter. Let it cool slightly before mixing.
In a large mixing bowl, combine the brown sugar and white sugar. Slowly pour in the browned butter and whisk until smooth. The sugars dissolve slightly into the warm butter, giving the cookies a chewy center with crisp edges.
Whisk in one whole egg plus one egg yolk (discarding the extra white). The yolk adds richness and helps create that soft, fudgy texture. Add the vanilla extract and mix until combined.
In a separate bowl, whisk together the flour and baking soda. Gradually add this dry mixture to the wet ingredients. Mix until just combined. Overmixing can make cookies tough.
Gently fold in the chocolate chips. For extra decadence, use a mix of chips and chopped chocolate bars so you get both gooey pools of chocolate and melty bites.
Cover the dough and refrigerate for at least 1 hour. Chilling helps control spreading, concentrates flavor, and gives you those bakery-style thick cookies.
Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper. Scoop 2–3 tablespoons of dough per cookie, spacing them 2 inches apart. Bake for 9–11 minutes until the edges are golden but the centers still look slightly undercooked.
Remove from the oven and immediately sprinkle with flaky sea salt. Let the cookies rest on the baking sheet for 30 minutes, then transfer to a wire rack. Resist the urge to eat right away. Allow them to set for 40 minutes. They’ll finish cooking through and become perfectly chewy.