Follow the instructions in this post here to learn how to brown butter in a 1-quart stainless steel saucepan. It's easy! Brown specks and a dense golden foam will form at the surface when it is nearly ready. This whole process takes around 8-10 minutes. Immediately pour it into a large mixing bowl, then let it cool for 20-30 minutes until it reaches a temperature just warmer than room temperature. If you care to measure, the butter should read between 32 and 34°C or between 90 and 93°F on a digital thermometer. It should be liquid still, but not hot. If it is too cool, it may stiffen up when you mix in the other ingredients.
Combine flour, baking soda, baking powder and salt in a medium bowl and whisk to blend evenly.
Add both sugars and vanilla to the bowl with the cooled brown butter and whisk until creamy, lightened and a bit fluffy. Whisk in eggs one at a time until well incorporated and creamy. Add the dry ingredients and fold them in until mostly combined, but a few streaks still remain. Add 1 ½ cups of chocolate chunks and fold them in until evenly combined.
Cover the bowl and refrigerate for 1 hour.
When ready to bake, preheat your oven to 350°F and two large cookie sheets with parchment paper. Use a 1.35-oz cookie scoop to portion dough into and roll into smooth balls. Place them onto prepared baking sheets, spacing them 3 inches apart. Press a few extra chocolate chunks on top of each dough ball. Bake for 8-10 minutes until golden on top, browned around the edges and soft in the middle. Let cookies cool on baking sheet for a minute before carefully transferring to a wire rack to finish cooling.