…can be a good thing if you’re talking St. Peter’s Basilica. If you’re talking about a cake layer…eh, not so much. Reader Tom wrote in this morning to ask what causes doming and what, if anything can be done about it. For indeed a cake layer with a big hump on it can be a pain in the next to stack and frost.
Doming is most often caused when the outer edge of the cake layer bakes up faster than the center. The surfaces areas around the outside edges firm up before the batter in the middle of the layer can fully expand. That leaves the batter no place to expand but inward. When those forces are ultimately felt in the very center of the layer, there’s nowhere for the expansion to go but upward, and you get a dome.
The best ways to eliminate this kind of doming is to a) make sure you oven isn’t running too hot and b) buy better, thicker cake pans. Thicker pans, being more massive, absorb heat more slowly and distribute it more evenly. The result is more even baking and a flatter layer. Some very obsessive bakers use things called “cake strips”, usually long, skinny, cloth-covered magnets (though the very new ones are heat-proof silicone loops that wrap around cake pans like big rubber bands). They add mass to the outside edge of the cake pan, causing it to heat more slowly. I don’t really recommend them unless you’ve got a truly horrible oven full of hot spots.
I should also mention that, depending on how you mix your cake, doming could also be the result of over-mixing. This typically doesn’t happen with the two-stage mixing method or the creaming method (over-mixing is most commonly associated with the muffin method), but of course it always pays to be alert and never mix more than you have to.
In the end, no amount of added mass, even heat and careful mixing can prevent cake layers from doming a bit. Mine below look very flat and even, but on close inspection you can see they have a subtle dome to them. I solve this, as all bakeries do, by slicing off the contours. For more on that see the post How to Prepare a Cake for Decorating under the Techniques menu to the right.