No one likes an undercooked cake and the bigger a cake pan you’re using, the more difficult it can be to achieve even baking without over-browning the top and sides of the cake. Heat radiates through the cake from the sides of the baking pan and, while not a problem for smaller cakes, larger pans will easily be overdone on the sides before they are finished in the center. To ensure even baking for large cakes – over 10-inches round, usually – some bakers will use a cake heating core.
The core is set inside the center of the pan before it is filled with batter (lightly greased on both the inside and the outside) and the cake batter is poured around it. A small amount is poured into the cake core itself to create a “plug” for the cake after it has baked. When the cake bakes, some heat radiates outward from the metal core, putting more of the batter closer to a direct heat source and baking a bit faster. The Baker’s Edge pan actually works on something of a similar idea, although the unusual shape of that pan wouldn’t be that useful for those looking to create layer cakes.
The only drawback is that the cake in the center “plug” may dry out slightly during baking. I’ve heard some bakers tell me that the cake insulates the core and prevents it from doing so, so it may just be over analysis of its texture on my part. In any case, the plug easily slips into the center hole left by the heating core and it’s impossible to tell that it was there once the cake has been frosted.
