2 sticks of cold, unsalted butter, cut into small pieces
1 cup packed dark brown sugar
3/4 cup granulated sugar
2 large eggs
Position oven racks in the lower and upper thirds of the oven. Preheat the oven to 350 degrees. Line two baking sheets with parchment and set aside.
In a medium bowl, sift the flour and baking soda. Mix in the salt. Set aside.
In the large bowl of a stand mixer fitted with a paddle attachment, beat half the butter on medium speed until smooth. Add both sugars and the remaining butter and beat for several minutes until the mixture is well combined, and the butter is light and fluffy. Add the eggs, one at a time. Add the dry ingredients and mix on low speed to combine. Mix in the chocolate.
Shape the dough into balls using two level tablespoons per cookie (hint: do NOT mess with this measurement; it produces the perfect-sized cookie). Bake for 12-14 minutes.