Preheat oven to: 375 degrees (F)
In a small bowl, combine flour, baking soda, and salt. (Whisk together)
In the Kitchenaid mixer bowl, use the paddle attachment at medium speed to cream together the butter, vanilla, and sugars. Add the eggs one at a time.
While the mixer goes, SLOWLY add in the dry ingredient mixture (slowly, or else it flies out everywhere). Then mix in the chocolate and nuts.
Put the batter in the fridge for 30 minutes or so ... cold batter is MUCH easier to work with.
I want large, soft cookies, so divide the resulting dough for exactly 24, or about 60g per cookie. I use a kitchen scale and a tablespoon to mine and weigh the dough, arranging them into 3 x 4 grids on two big cookie sheets. Space them out ... the dough melts and spreads, so you don't want them running into each other too much.
The cook time says 9-11 minutes, but that's for smaller cookies than what I'm making here. Start watching after 15 minutes so they don't burn, but cook time will be closer to 20 minutes.
Remove the cookie sheets from the oven. This may not be at the same time ... for whatever reason, the upper cookie sheet always seems to be ready before the lower one.
Let the cookie sheets cool for 5-10 minutes (don't rush it, or else the cookies just fall apart when you try to move them) then carefully twist and move each cookie to a wire rack to finish cooling. (I use a slotted metal spatula which helps a lot.)