Preheat the oven to 350F then grease a 10-inch cast-iron skillet and set aside.
In a large bowl, cream the butter, brown sugar, and granulated sugar until combined. Add in the eggs and the vanilla and mix again until everything is incorporated.
Mix in the flour, corn starch, baking soda, and salt, just until the flour disappears. Mix in th emini chocolate chips and the roughly chopped Oreos.
Spread the batter onto the prepared castiron skillet, tip with 2-3 roughly chopped up Oreos and a few more mini chocolate chips and bake in the preheated oven for 23-25 minutes. Make sure not to overbake your skillet cookie.
Remove from the oven and let cool for 10-15 minutes before topping with ice cream and enjoying!