Preheat the oven to 350°F. Grease a 12-inch cast iron skillet and set aside.
In a large saucepan, melt the butter over medium heat. Add the sugar and stir to combine. Return the mixture to the heat and stir until smooth and the mixture is shiny.
Remove from heat and stir in the cocoa, baking powder, salt, and vanilla extract.
Whisk in the eggs, stirring until smooth.
Add the flour and chocolate chips. Stir until just combined.
Pour the brownie batter into the prepared skillet. Drizzle the salted caramel sauce over the brownie batter and gently swirl the caramel into the batter with a knife.
Bake the brownies for about 30-35 minutes or until a toothpick inserted into the center comes out with just a few moist crumbs clinging to it. The brownies will be a little gooey. Remove the skillet from the oven and cool completely on a rack before cutting and serving. Serve with ice cream and additional salted caramel sauce, if desired.
Note: If you don't have a skillet, you can use a 9x13 pan.