Preheat oven to 350 F / 177 C / gas mark 4. Butter a 10-inch cast iron skillet.
Combine flour, baking soda, and salt in a small bowl. In large mixing bowl, cream butter about 1-2 minutes. Add sugars and cream together until lighter in color and fluffy, about 2 minutes. Add eggs and vanilla and mix until combined. Pour the flour mixture into the butter/sugar mixture and stir just until combined. Stir in chocolate chips.
Spread dough into prepared cast iron skillet. Make sure to spread evenly into edges of pan.
Bake at 350 for about 35-45 minutes, or until the top is golden, the edges are set, and a toothpick inserted into center comes out clean. Let cool for about 15-20 minutes before cutting. Serve warm with vanilla ice cream.