Psychedelic Brownies in Vintage Cast Iron Skillets

In our home, we have pretty much abandoned cake for birthdays. I made these cast iron brownies for my wife's birthday celebration. I preheated the skillets to 350°, greased them, and then added the brownie mix. Yellow cake mix was added to a condiment bottle and then swirled on top of the brownies. Chopped walnuts were added and then the brownies were baked for about 30 minutes. Topped with vanilla ice cream and chocolate syrup.