Combine butter and sugars in the bowl of a stand mixer. If butter is coming straight from the fridge, microwave for 15 seconds on high to soften. Mix for 3-4 minutes, scraping sides of bowl, as needed. Add eggs and vanilla and mix another 1-2 minutes, until light and fluffy.
Add flour, soda, cream of tartar and salt. Mix until combined. Add chocolate chips and mix on low until evenly distributed.
Spread dough into a 10” cast iron skillet. Sprinkle with sea salt (if desired). Bake for 22-24 minutes until golden brown on the edges.
Let cool for about 10 minutes, then top with vanilla ice cream and eat right out of the skillet.
* If you don’t have a skillet, you can make a pizookie in an 8-9” round pan or pie pan. It won’t be as crusty around the edges, but will still be delicious!