Preheat the oven to 350°F (175°C). Lightly grease a 10-inch cast-iron skillet.
In a large bowl, whisk together melted butter, brown sugar, and granulated sugar until smooth.
Add eggs and vanilla extract, then mix until well combined.
In a separate bowl, whisk together flour, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, stirring until just combined.
Fold in the chocolate chips.
Spread the dough evenly into the prepared skillet.
Bake for 25-30 minutes, or until the edges are golden brown but the center is slightly soft.
Let cool for 10 minutes before serving. Enjoy warm with a scoop of ice cream!