Preheat oven to 350°
Melt butter in 10-inch cast iron skillet over low to medium heat. Remove from heat once butter is melted.
Combine brown sugar and white sugar in a medium mixing bowl and stir in melted butter. Stir and combine well. Let it rest for 4 minutes and stir again.
Add eggs and mix well.
Combine flour, baking soda, and salt in a bowl.
Mix in flour mixture to sugar and butter mixture. Mix well.
Add chocolate chips and stir to combine into the mixture.
Pour chocolate chip cookie batter into 10-inch cast iron skillet. Spread out evenly.
Bake in a 350° oven for 20-25 minutes or until golden brown.