Brown the Butter:

1. Browning butter happens quickly and can go from perfect to burnt very quickly so keep an eye on your stove and a heat-proof dish nearby.
2. Place 2 tablespoons butter in a pan on medium heat and whisk consistently.
3. As the butter melts, it will start to froth and sizzle. It will turn golden brown in about 5-8 minutes and release a nutty aroma.
4. Immediately remove the pan from the heat and pour the butter into your heat-proof dish to halt the cooking.
5. Whisk the espresso powder into the brown butter and allow to cool in heat-proof dish for 5-10 minutes.

Make the Dough:

1. In a medium bowl, whisk together the all-purpose flour, baking soda and salt. Set aside.
2. In a large bowl, using a hand mixer or a stand mixer fitted with a paddle attachment, beat the brown butter espresso powder mixture on high speed for 1 minute until creamy.
3. Switch to medium-high speed and add the granulated sugar and brown sugar. Beat until the mixture is completely creamed and smooth, about 2 minutes.
4. With the mixer on low speed, add the eggs to the mixture and beat until well combined. Scrape down the sides and bottom of the bowl as needed.
5. Next, add vanilla extract. Beat until everything is well combined.
6. On low speed, gradually add the flour mixture to the wet ingredients and beat until combined. Be careful not to overmix the dough.
7. Pour pecans and dark chocolate chips into the batter and fold in by hand to incorporate.
8. Using a medium cookie scoop (1.5 tablespoons), scoop dough and roll it into a ball.
9. Chill the cookie dough balls for at least 1 hour.
10. Once dough is chilled, preheat oven to 350°F and line two large baking sheets with parchment paper or silicone baking mats.
11. Place cookie dough on baking sheets, spacing 2 to 3 inches apart and sprinkle with sea salt.
12. Bake for 10-12 minutes, rotating the pan halfway through. The cookies are done when the edges of the cookie just begin to turn golden brown and the centers look slightly under-baked.
13. Remove the pan from oven and allow the cookies to cool on the cookie sheet for 3 minutes before transferring to a cooling rack to cool completely.