Preheat oven to 350 degrees F. In a medium bowl, combine flour, baking soda and salt. Set aside.
In a large mixing bowl beat the butter on high speed for a minute or so. Add the brown sugar, granulated sugar, egg and vanilla. Beat until mixture is combined just about a minute, scraping sides of bowl occasionally.
Stir in flour mixture until combined. Fold in chocolate chips and pecans.
Drop dough by rounded teaspoons 2 inches apart onto an ungreased cookie sheet. Bake for 7 or 8 minutes or until edges are lightly browned but still soft and slightly wobbly in the middle.
Remove from oven and while still warm, slightly flatten each cookie gently with the back of a spatula. This makes the cookie a little denser.
Let cool a few minutes before transferring the cookies to a wire rack. Once cooled completely can be stored in an airtight container for about a week.
