When I worked at Godfather's Pizza years ago. They made a deep dish pizza. To cook the inside of the pizza they used a cast iron device. From the top it looked like a spider web. From the side you could see spikes that went down into the pizza. We would coat it with spray and then insert into the pizza. It help cook the midde since there was two layers of crust.
Does anyone know what I am refering to or anywhere to get one?