Preheat oven to 350°F. Lightly grease a 10- to 12-inch cast-iron skillet or baking dish and set aside.
In a large mixing bowl, mix together melted butter, granulated sugar, and brown sugar until well combined.
Beat in the eggs, one at a time, followed by the vanilla extract.
Add flour, baking soda, baking powder, and salt and continue mixing until combined. Stir in the chocolate pieces/chips.
Spread the dough evenly into the prepared skillet. It's going to be sticky and that is totally normal.
Bake for 22–26 minutes, or until the edges are golden brown but the center is still soft and slightly underbaked. Let it cool for about 5 minutes before serving.
Top with vanilla ice cream, whipped cream, and a drizzle of chocolate sauce, and/or caramel sauce. Serve while the cookie is still warm.