Start by melting the butter in your cast-iron skillet or a small saucepan.
In a large bowl, whisk together the melted butter, brown sugar, and white sugar until smooth and glossy. Add the eggs one at a time, whisking well after each addition.
Then stir in the vanilla extract.
In another bowl, whisk together the flour, baking soda, and salt. Slowly fold the dry ingredients into the wet mixture using a spatula.
Once it comes together, fold in the chocolate chips
Lightly grease a 10-inch cast-iron skillet or oven-safe pan with butter. Spread the cookie dough evenly, pressing it into the edges so it bakes evenly.
Bake at 350°F (175°C) for 20–25 minutes.