Hi and welcome to Cake Central!! You can use a heating core, but here is a much easier and less trouble way to do it. Do you have a Flower Nail??
If so, just spray with pam and turn it upside down in the middle of your pan. It will do the same thing the heating core does without the huge hole in the middle of your cake.
When you take the cake out of the oven, let it cool
for a few mins and then invert it onto a cooling rack. When you remove the pan, you can pull the nail out from the bottom of the cake and then flip the cake back to upright position.
One more little tidbit. If you are making a large cake 12x18 or more, you can use 2-3 flower nails
evenly spaced in the pan. Also, if your cake is cooked way over the top of the pan, you should trim it before you flip it out of the pan or it is liable to break ( I have had the unfortunate experience a couple of times)...
Hope this helps...
Cindy
Hi Bev,
Welcome to CC 
Cindy answered your heating core question, so I'll give you a tip.
Instead of greasing/flouring or using Wilton cake release for your cake pans; you can make your own cake release (pan grease).
Mix together 1 part each: crisco, vegetable oil and flour. Doesn't require refrigertion and really, really works great!
Also, the bake even strips are quite popular.
Here's a list of acronyms:
http://www.cakecentral.com/cake-decorating-ftopict-2926-acronyms.html
Quote by @%username% on %date%
%body%