Preheat oven to 350 degrees F. 

Rub a 12 inch, deep cast iron skillet with softened butter to lightly coat. Set aside.

In a large mixing bowl and using either a stand mixer or hand mixer, beat together butter with granulated sugar and brown sugar until smooth. Add eggs and vanilla extract and beat until just barely combined. 

In a separate bowl combine flour, baking soda, and salt. Add the flour mixture to the egg mixture and combine. Fold in the chocolate chips. 

Pour out cookie dough into prepared cast iron skillet. Place in oven, middle rack, and let bake 22-27 minutes or until the edges start to turn light golden brown. 

Remove from oven and let cool before serving.