Preheat oven to 350 degrees
I large mixer bowl, combine butter and sugars. mix on low for 5 minutes.
Stir in eggs and vanilla. Mix for another 5 minutes.
Stir in flour, baking soda, and salt. Mix for 5 minutes.
Add chips and mix to combine.
Add chopped walnuts ( See Note ) if desired, and mix for 5 minutes.
Transfer dough to lightly oiled 10" Cast Iron Skillet and smooth out dough with wooden spoon.
Place wax paper on top of dough, and use bottom of 5 Qt. Dutch oven to press the dough.
Remove wax paper, bake for 20 minutes. Let cool for 20 minutes, slice an serve.