Preheat the oven to 350ºF. Coat a 12 inch cast iron skillet with cooking spray and set aside.
In a large pot or dutch oven, melt butter over medium heat. Add the sugar and whisk until smooth and shiny.
Remove the pan from the heat and whisk in cocoa, salt, and vanilla extract.
Add the eggs and whisk until smooth.
Using a rubber scraper, fold in flour and chocolate chips until just combined.
Transfer the batter to the prepared skillet and smooth the top. Bake 25-30 minutes or until a toothpick inserted near the center comes out with moist crumbs clinging. Be careful not to over bake. Allow the brownies to cool a bit while you prepare the caramel topping.
Caramel Cashews
In a 2 quart heavy bottomed sauce pan, place 1 cup sugar over medium heat. As the edges begin to melt, gently push the liquid sugar up over the granulated sugar with a rubber scraper to help it melt. When all the sugar is melted allow it to cook until it becomes a dark amber color.
Remove from the heat and carefully add the butter and heavy cream, stirring until smooth. Return to the heat and bring to a boil, then reduce the heat to low and allow to simmer undisturbed for 3 minutes.
Remove from the heat and allow the caramel to cool for 10 minutes before adding the cashews and stirring until incorporated.
Taste and add sea salt if desired. Pour the caramel over the brownies and serve.