Preheat oven to 350ºF. Grease a 10 inch cast iron skillet and set aside.
Using a mixer, cream together butter and sugar in a large bowl for about 2 to 3 minutes or until pale.
Add eggs and vanilla then continue mixing until completely blended.
Next add in in flour, baking soda and salt then continue mixing until combined.
Add in your chocolate chips and mix until fully incorporated.
Spread half of your dough in your greased skillet
Top the dough with your Nutella then spread it out evenly using a spatula. (You can warm the Nutella slightly to make it spread more easily.)
Next drop dollops of your remaining dough over the Nutella trying to cover the Nutella as much as you can.
Bake in your preheated oven for 20 to 30 minutes depending on how thoroughly baked you want it to be. (I baked mine for 30 minutes and got a darker cookie with a more set center.)
Drizzle with Nutella and let it cool for 5 to 10 minutes. Serve warm with a scoop of vanilla ice cream if desired.
