Position racks in the center and top third of the oven and preheat to 350 degrees F. Line two large baking sheets with parchment paper.
Sift the flour, baking soda, and salt into a medium bowl. Set aside.
In the bowl of a heavy-duty stand mixer fitted with the paddle attachment, cream the butter, brown sugar and granulated sugar on medium speed until well blended, about 2 minutes; scrape down the bowl.
Beat the eggs and vanilla in a small bowl. Add to the butter mixture and blend well; scrape the bowl again. On low speed, add the flour mixture and beat until just mixed; scrape down the bowl. Add the chocolate and optional nuts and mix until incorporated into the dough.
Drop rounded tablespoons of the dough onto the prepared sheets, spacing them about 2 inches apart. Bake, switching the position of the sheets from top to bottom and front to back halfway through baking, until the cookies are golden brown but the centers seem slightly underdone, about 13 minutes. Do not overbake or the cookies will be crisp throughout instead of chewy. Cool for a few minutes on the baking sheets, then transfer to wire cooling racks to cool completely. The cookies will crinkle as they cool. (Store at room temperature in airtight containers for up to 1 week.)
Courtesy of Scharffen Berger Chocolate Maker