Baking is a science, and it’s helpful if you approach it as such, as if each cake you bake is a lab experiment that will help you refine your technique. There are so many variables that can contribute to a cake that breaks, but here are a few simple tweaks you can make that will give you more reliable results. The batter: First, and probably most simply, you can pay attention to the batter. If the batter is too thick, it won’t spread as well, and you’re more likely to have it break.
If the batter is too thin, it will spread too much, and again, is likely to break. Take a minute or two to pay attention to the batter the next time you mix up a cake recipe. You want it to be somewhere in between, where it slowly drips off the spatula, but isn’t gloopy or runny. Try mixing a cake recipe one day, and then again a day or two later, holding everything constant except for maybe a minute or two less in the mixing time. I bet you’ll see a difference in how the batter comes together. How you mix your ingredients: Second, pay attention to how you’re mixing the ingredients together.
If you mix them too quickly, you’re introducing too much air into the batter, which can cause the center to be too airy, and consequently can cause the cake to break. Another mixing issue is mixing for too long, especially after you add in the flour. This develops the gluten in the cake too much, and can cause it to be dense, or to break. If you notice the batter is very shiny and smooth, you’ve probably mixed it too long.
When you add in the flour, mix just until it disappears, even if it seems like you’re not mixing long enough. Finally, the temperature in the oven can have a huge effect on whether or not the cake breaks. If you open the oven door too soon, it causes a temperature fluctuation which can cause the cake to break. Try to avoid opening the oven door until at least half way through the baking time. I like to put a small hash-mark on the timer when I’m allowing myself to open the oven door to check on the cake.
Do this a few times, and you’ll start to train yourself to wait. To practice this, you can do a small test in about 15 minutes of prep time. Pick one variable to change (maybe you’re mixing the batter a little longer than usual, or using colder butter and eggs than usual), mix up a small batter, take note of one thing you notice about the batter (maybe how it pours into the pan?), then pop it in the oven. You don’t want to change too many variables at once, or you won’t be able to isolate what the problem is.
And finally, if your cake does break, take note of what might have caused it. What was the batter like? How long did you mix it? Did you open the oven door too soon? Fix these issues, and try again. One of the biggest keys to baking successfully is not necessarily trying new recipes and techniques, but going back and trying the ones that failed again and again until they become second nature.