Reader Melissa writes:
I have an issue and I know if no one else can, you can tell me why I am having it. Everytime I bake a cake, the middle cones up and it splits. I checked through your tutorial but didn’t find an article on it. So I decided to write.
Thanks for writing in with this, Melissa, since it’s an extremely common problem. There are two main causes for bulge-in-the-middle cake layers. The first is over-mixing. Too much agitation creates a lot of activated gluten. Think of gluten as a stretchy network of rubber band-like molecules that’s trying to pull the cake together into a ball as it heats. It’s a very common cause of crowning — especially in muffins, the tops of which are often cone-shaped (a sure sign of a pasty, chewy product).
The other major cause is an overly hot oven, and flattish items like cake layers are especially vulnerable to a hot oven’s effects. The outer regions of the layer heat up quickly and set prematurely, the consequence being that their surfaces become rigid. This holds in the rise like a girdle, so as the un-baked batter in the middle of the layer heats it has nowhere to expand — except inward toward the center.
As the process continues the very center of the layer becomes compressed, and as the last of the un-baked batter that’s located there heats, it has nowhere to expand but upward. The result is a pronounced crown and usually some very severe cracks as the expanding batter pushes up through the layer’s rigid surface.
So my guess, Melissa, is that your oven is running hot. Try calibrating it with an oven thermometer: turn the oven to say, 350, put in the thermometer and move it from place to place to check the temperature in different spots (most ovens have hot and cold spots). Raise the temperate to 400 and try it again, since ovens behave differently at different settings. After an hour or so you should have a feel for how your oven is behaving and can adjust accordingly. Get back to me if you’re still having problems!