Preheat the oven to 350°F and grease a 12-inch cast iron skillet with butter.
In a medium mixing bowl, whisk together the flour, baking powder, and salt. Set the bowl aside.
In a stand mixer fitted with the paddle attachment, cream together 1 cup (2 sticks) unsalted butter with the sugar and light brown sugar.
Add eggs, one at a time, until mixed in, then add the vanilla extract and beat until combined.
Add the flour mixture into the stand mixer and mix just until the dough comes together then beat in the chocolate until combined.
Scrape the dough into the skillet, then sprinkle it with the sea salt.
Bake the cookie for 30 to 35 minutes until it’s barely cooked in the center.
Remove it from the oven and allow it to cool for 10 minutes before serving topped with ice cream (optional).
★ Did you make this recipe? Don't forget to give it a star rating below!