In a large mixing bowl, cream together the butter, brown sugar, and granulated sugar until light and fluffy.
Beat in the eggs one at a time, then stir in the vanilla extract.
In another bowl, whisk together the flour, baking soda, and salt. Gradually add this to the wet mixture, mixing until just combined.
Fold in the chopped pecans.
Drop dough by rounded tablespoons onto ungreased baking sheets.
Bake for 10-12 minutes, or until edges are golden brown. Allow cookies to cool on baking sheet for a few minutes before transferring to wire racks to cool completely.