Heating cords are a great product if you are baking batter an 8-9-10-12-14-16 inch pan. If you do not use a heating core the middle of your cake will be raw. Nature of the beast. And don't forget to fill the core halfway with batter also, batter holds it in place and you can fill the hole after baking with the cake in the core. Also don't forget to butter and flour the inside of the core so you're baked goods will pop out easily.