In a bowl, with an electric mixer on medium speed, beat butter, brown sugar, and granulated sugar until well blended. Beat in 3 tablespoons water and the vanilla until smooth, scraping down sides of bowl as needed.
In another bowl, mix flour, baking soda, and salt. Stir or beat into butter mixture until well incorporated. Stir in chocolate chips and pecans, if using.
Drop dough in 1-tablespoon portions, 2 inches apart, onto buttered 12- by 15-inch baking sheets.
Bake in a 300 oven until edges of cookies are browned, but an area about 1-inch wide in the center is still pale, about 14 minutes; if baking more than one pan at a time, switch pan positions halfway through baking.
With a wide spatula, transfer cookies to racks to cool. If hot cookies start to break, slide a thin spatula under them to release; let stand on pan to firm up, 2 to 5 minutes, then transfer to racks to cool completely.
