Browned Butter Chocolate Chip Cookies with Walnuts and Bourbon

0 Melt [wprm-ingredient text="0.5 cup salted butter" uid="0:1"] of the butter (one 8-tablespoon stick) in a medium skillet over medium heat. Stir or swirl frequently. The butter will crackle and bubble as it cooks, as well as begin to smell nutty. Brown 'crumbs' will form in the bottom of the skillet, so continue to stir until these crumbs turn medium brown in color, about 2 ½ to 3 minutes. Remove the skillet from the burner and pour the brown butter into a heat-proof bowl, crumbs and all. Let cool for at least 20 minutes. This part can be done in advance. Brown butter can be kept in the refrigerator for a few days in an airtight food container.
1 Sift together the [wprm-ingredient text="2 ¼ cups all-purpose flour" uid="1"], [wprm-ingredient text="1 teaspoon baking soda" uid="2"] and [wprm-ingredient text="½ teaspoon kosher salt" uid="3"] into a medium bowl. Set aside.
2 Add the remaining [wprm-ingredient text="0.5 cup salted butter" uid="0:2"] (one 8-tablespoon stick) with [wprm-ingredient text="¾ cup dark brown sugar" uid="4"] and [wprm-ingredient text="¾ cup granulated sugar" uid="5"] into a large bowl. Mix with a hand or stand mixer for 3 to 5 minutes, until the mixture is smooth, creamy and light in color.
3 Pour the cooled brown butter into the bowl with the butter and sugars.
4 Beat for 2 minutes, until smooth.
5 Measure in the [wprm-ingredient text="2 large eggs" uid="6"], [wprm-ingredient text="2 teaspoons pure vanilla extract" uid="7"] and [wprm-ingredient text="2 tablespoons bourbon whiskey" uid="8"]. Mix until combined.
6 Gradually stir in the flour mixture, blending until thoroughly combined.
7 Measure in the [wprm-ingredient text="½ cup chopped milk chocolate" uid="9"], [wprm-ingredient text="1 ½ cups chopped bittersweet chocolate" uid="10"] and [wprm-ingredient text="½ cup coarsely chopped walnuts" uid="11"], stirring with a wooden spoon or rubber spatula until incorporated.
8 Wrap the bowl in plastic wrap, and refrigerate for at least 2 hours.
9 Preheat oven to 375ºF. Line a baking sheet with parchment paper and set aside.
10 Use a 1.5-tablespoon cookie scoop to drop dough onto the prepared baking sheet, about 3-4 inches apart. Sprinkle the tops of the cookies with [wprm-ingredient text="¼ cup demerara sugar" uid="12"].
11 Bake for 9-11 minutes or until golden brown.
12 Remove from oven and let cool for 1-2 minutes on the baking sheet, then transfer to a wire baking rack to cool, or serve warm.