Add wet ingredients: Add the softened butter and granulated sugar to the large bowl of a stand mixer, or a mixing bowl if you are using a hand mixer/spoon.
Freeze: Put the cookie dough in the freezer for 15-20 minutes, to allow for the butter to firm up. Transfer the cooled dough to a greased cast iron skillet.
Bake the cookie: Bake the cookie for 15-20 minutes. It will still appear soft, but will firm up as it cools down. The best way to serve is to top with vanilla ice cream, and optionally, caramel sauce as well!