Whisk together flour, baking soda, and espresso powder in a medium bowl and set aside.

In a saucepan over medium-high heat, melt 1 stick of butter (8 tablespoons). Continue cooking until butter begins to brown. Swirl pan constantly until butter has foamed and takes on a dark golden brown color and smells nutty. Watch carefully, as it can quickly go from dark to burnt. Carefully pour browned butter into a large heat-proof bowl, scraping all the browned bits from the pan by using a heat-proof spatula.

Immediately whisk the remaining butter pieces into the browned butter, until melted. Add sugars, salt, and vanilla to the bowl, and whisk to fully incorporate.

Add egg and egg yolk and whisk until smooth with no lumps remaining, about 30 seconds. Let mixture stand for 2-3 minutes to let the sugars melt, then whisk for another 30 seconds. Repeat this rest-and-whisk process 3 times, total. Mixture should seem thickened, smooth, and shiny.

Using a spatula, stir in dry ingredients until just combined (and a few flour streaks still remain). Stir in chocolate chips, discs, and nuts until evenly distributed and no flour pockets remain. Refrigerate dough for at least 2 hours, or overnight.

Once dough has chilled, scoop into balls that are slightly bigger than a golf ball. (At this point, I put them on a quarter sheet tray in the freezer, once frozen solid, I transfer them to a resealable freezer bag, so I always have homemade CCC dough at the ready!).

Place cookies 2” apart on baking sheets lined with parchment or a SilPat.

Bake in a pre-heated 375°F for 10-14 mins until cookies are golden brown and puffy in center, but edges are darker and have set. Transfer cookie sheet to a rack to cool completely (or at least 10 mins if you can wait that long).

If baking from frozen, let dough balls sit out for 10-20 mins while oven preheats to 350°F and bake for 16-20 mins.