1. Preheat the oven to 350° and position racks in the middle and lower thirds of the oven. In a medium bowl, whisk the flour with the baking soda and salt.
2. In a large bowl, using a handheld electric mixer, beat the butter at medium speed until creamy. Add the brown sugar and granulated sugar and beat until light and fluffy. Add the eggs and vanilla and beat until smooth. At low speed, beat in the dry ingredients. Stir in the chocolate chips and nuts.
3. Arrange tablespoons of the cookie dough at least 1 1/2 inches apart on 2 large baking sheets and bake for about 11 minutes for soft and chewy cookies, about 13 minutes for chewy cookies or about 16 minutes for crisp cookies. Let the cookies cool on the baking sheets for 2 minutes before transferring them to wire racks.
Make Ahead: The cookies can be stored in an airtight container between sheets of wax paper for up to 2 days.