First, let’s brown the butter. Put 2 sticks of unsalted butter in a light-colored saucepan over medium heat (light-colored helps you see the browning better). Keep stirring occasionally and watch carefully – you’ll see little golden-brown specks forming at the bottom and it’ll smell wonderfully nutty, like toasted hazelnuts. This usually takes about 5-7 minutes. Pour it into a heat-safe bowl right away to stop the cooking and let it cool for about 20-30 minutes until just warm to the touch.
While the butter cools, get the dry ingredients ready. Whisk together the flour, baking soda, and salt in a bowl. This helps distribute everything evenly so you don’t bite into a pocket of salt later.
Once the brown butter has cooled but is still slightly warm, add both sugars and mix really well with a wooden spoon or spatula. You want the sugars to almost melt into the warm butter – this gives you that chewy texture later. The mixture will look like wet sand.
Beat in eggs one at a time, mixing well after each. You’ll see the mixture get smoother and lighter in color. Now add the bourbon and vanilla – the bourbon adds a lovely caramel note that works magic with the brown butter.
Gradually stir in flour mixture until just combined. Stop as soon as you don’t see any dry flour – overmixing makes tough cookies. The dough will be pretty soft at this point.
Fold in the chocolate chunks and pecans. Make sure pecans are completely cool from toasting or they’ll melt the chocolate. The dough will be thick and chunky – that’s exactly what we want.
Here’s the hard part – chill the dough for at least 2 hours or overnight. This lets the flour hydrate and helps prevent flat cookies. I know it’s tempting to skip this, but trust me, it makes a difference.
When you’re ready to bake, preheat your oven to 350°F and line your baking sheets with parchment. Scoop generous tablespoons of dough (about 3 tablespoons each) onto your sheets, leaving plenty of space between them – these spread a bit.
Sprinkle each cookie with a little flaky sea salt. The contrast with the sweet dough is fantastic.
Bake for 11-13 minutes, rotating the pan halfway through. Look for golden brown edges but a slightly lighter center – they might look a tiny bit underdone in the middle but will set up as they cool. The perfect cookie should have a slight dome with crackly top.
Let them cool on the baking sheet for 5 minutes – they’re too soft to move right away. Then transfer to a wire rack to cool completely.