I get it: sometimes you want to make a cake, and you just don't have the pan the recipe calls for. An 8-inch round pan is basically the same as a 9-inch round, right? (Right?!?) I mean, the pan just holds the batter, you tell yourself. What does the size, or shape, really matter, anyway?
The truth is, it actually matters a lot. It's always best to follow a recipe—especially baking recipes—as written. The baking time, ingredient amounts, and, yes, pan size are all intrinsically important to the success of the dish.
But very few home cooks (and honestly, very few professional bakers) keep every single size pan in their cabinets. So what's a well-meaning host to do if they want to make a cinnamon streusel coffee cake for a Sunday-morning brunch but don't have any Bundt pans on hand? I reached out to two of the biggest #BossLady bakers I know, Baking Bible author Rose Levy Beranbaum and Flavor Flours author Alice Medrich, to find out the right ways to bend the baking pan rules. Here's what they suggested:
1. Don't Assume Every Pan Is Equal
A 9-inch round cake pan might look a lot like an 8-inch round one, but in truth, their volume isn't nearly as close as you think. "A 9-inch round is actually 25 percent bigger," explains Medrich, noting that if a recipe calls for an 8-inch round pan and you use a 9-inch round pan instead, "you’re going to have a very thin cake, because it has to cover 25 percent more surface area."
"If the pan is too big, the sides shield the batter and slow down the baking," says Levy Beranbaum, explaining that the resulting cake will be drier and paler than intended. "If the pan is too small, the batter will run over the sides and the cake will collapse from inadequate support."
But there are a few pan swaps that are easy to make. "A 9-inch round cake can be baked in an 8-inch square pan," says Levy Beranbaum. And "loaf pans and tube pans are a little interchangeable," says Medrich, "because they are both deep and aren't wide and expansive, but then you have to compare how much volume they hold."
2. Get Down With Arithmetic
Which brings us to the fact that size does matter—and so does math. "It’s pretty basic arithmetic," says Medrich. If that 9-inch pan is 25 percent bigger, all you have to do is increase the recipe by 25 percent. "It’s not anything more than square areas and percentages," she says. "You can do it by volume. If you're using cups and spoons, you can still increase the recipe by half or a third." To divide eggs, she suggest whisking the egg first, then using half of it.
Not so sure of your math skills? You read the nitty gritty of Medrich's baking equation, broken down into a simple formula, over on Food52.
