Drag a knife around the edge. Gently slide a butter knife between the sides of the pan and the edges of the cake. Don't cut into the cake itself, just fill in the gap between the edges of the pan and the cake. Drag the knife all around the cake pan to loosen up any grip the edges still have on the sides.
Cool Before Flipping
When you remove your cake from the oven, don't flip it out of the pan right away! Instead, let the cake cool for ten minutes in the pan. Then, placing the wire rack over the base of the cake, invert the pan. Peek under the wire rack and see if the cake has dropped out.
When the cake first comes out of the oven, it's cooked through but the hot "crumb" — the mass of the cake — is delicate. If you try to get it out of the pan too soon it can stick to the pan, break, or both. For most cakes, allow around 20 to 30 minutes at room temperature for cooling (per MasterClass).
It's important to pay attention to the specifics called for in a recipe, but in general, most cakes are best removed from the pan after cooling for 10 to 20 minutes. Try it too soon, and it may fall apart. Wait too long, and it may stick.
You didn't grease your pan.
If you poured your batter straight into the cake tray and placed it in the oven, there's your mistake. I recommend greasing your pan with shortening, but vegetable oil or butter will certainly work in a pinch. Stick with lightly flavored oils; steer clear of olive oil.
Make sure that your warm cake is given at least 10 minutes to sit in the pan after it is taken out of the oven. This rule applies as the first step to any cake cooling method.
Before You Start
Attempting to spread frosting onto warm cake layers is a recipe for sloppy disaster. Chill your cake layers for at least 2 hours, or better, overnight. If you've made your frosting ahead, make sure it's at room temperature before you start.
Recipes will usually give instructions for cooling but as a general rule, most sponge cakes are best left for a few minutes and then turned onto a cooling rack to avoid soggy edges. Rich fruit cakes are better cooled in the tin.
Our answer. Unfortunately once a cake has cooled it is not possible to re-bake it.
Silicone-coated baking paper (parchment) is the cake baker's best friend. Line the bottom of your pan with nonstick parchment, then coat the pan's sides with nonstick pan spray.
I use a very heavy coating of non-stick baking spray that includes flour (like Baker's Joy), but you can also use a coating of butter and flour. Let the cake cool, but not completely. Before you flip the cake upside-down, let the cake cool in the pan for 10 minutes to let it finish setting up.
It won't come out quite right
So, in your attempt to remove the cake from the pan the cake will struggle to come out, which will often result in the crumb tearing or falling to pieces.
Yes, you can put your cake in the fridge to cool, provided you let the cake cool briefly (about 5 to 10 minutes) on the countertop first. If you don't allow a little cooling outside the fridge first, there is a risk of the cake sinking in the middle or sticking firmly to the sides of its pan.
For a clean release, grease, flour—and parchment—are key. It may sound like overkill, but the most effective way to ensure that a cake releases cleanly from a baking pan is to grease the pan, line it with parchment paper, and then grease and flour the parchment and pan sides.
Rely on room temperature.
You can leave out your covered cake overnight without even wrapping it, and it should be fine in the morning. For any amount of time longer than that, make sure to wrap it in something.
Whether you're serving it to guests or simply indulging yourself, a cake that's not moist is just sad. But there's an easy way to prevent this dryness, and it only takes a few seconds. According to The Kitchn, you should try wrapping hot cake layers in a pantry staple — plastic wrap. That's right, plastic wrap.
Let your baked cake cool on its own before doing anything to expedite the cooling process. Ten minutes at room temperature is usually enough time. Store your hot cake on a flat surface like a countertop or cake stand for that period of time.
First, try covering the cake with aluminum foil and baking it for 5-10 minutes. This will help trap the heat and help the cake cook more evenly. If the cake still doesn't seem done, try cutting away the undercooked portions and topping the cake with frosting or another topping of your choice.
To avoid soaking your cake in a melted slurry of butter and sugar, you'll need to let it cool first. Even if you start with a cake that's warm and not quite hot, it will probably make a disaster out of your frosting. It could even be worse if your frosting ends up partly melted and partly firm.
Attempting to work with a warm cake is no joke, especially if you're trying to trim it. The crumb will not be fully set until cool, so when you cut into it, the sponge will be prone to falling apart, or it'll tear completely, which harms the intended shape of your cake (via CupcakeJones).