In a medium bowl, sift together flour, baking soda and salt.
In the bowl of an electric mixer, fitted with the paddle attachment, beat the butter and brown sugar, on medium speed, until well blended. Beat in the eggs and vanilla until well blended, scraping down sides of bowl as needed. Add flour mixture; mix just until blended. Stir in chocolate chips and pecans, if using. (Optional: cover dough and chill 20 - 30 minutes.)
Drop dough in 2-tablespoon portions, 2 inches apart, onto baking pans. Bake until the cookies are lightly browned and no longer wet in the center, 6 to 8 minutes; if baking more than one pan at a time, switch pan positions halfway through baking. (Take the cookies out of the oven 1 or 2 minutes before the cookies are cooked, as they will continue to cook on the baking pans.)
Let cookies cool for 5 minutes on baking sheet before transferring cookies to racks to cool completely before serving.