Place your unsalted butter in a medium saucepan over medium heat. Stir as it melts, and soon you will see foam forming on top. Keep stirring so it does not burn. In a few minutes, small brown bits will form at the bottom, and the butter will smell nutty and rich. Once golden brown, take it off the heat right away and pour it into a mixing bowl to cool slightly.
Add the brown sugar and granulated sugar to the warm butter and whisk well. The mix will look thick and glossy. Next, stir in the eggs and vanilla until smooth.
In another bowl, whisk the flour, baking soda, and salt. Add this dry mix to the wet ingredients. Stir gently until you have a soft cookie dough.
Fold in the chocolate chips. If you want nuts, add them now, too. The dough will be thick but soft.
Cover the bowl and chill for at least 30 minutes. This step helps the cookies hold their shape and gives them that chewy texture.
Preheat your oven to 350°F (175°C). Scoop the dough onto a parchment-lined baking sheet, about 2 tablespoons per cookie. Leave space between each one. Bake for 10–12 minutes, until the edges are golden, but the centers still look soft. Let them cool for a few minutes on the baking sheet before moving them to a wire rack.