Super quick thought - have you ever wondered how to tell if your cake layers are done baking? Well, the answer is NOT to set the timer for however long the recipe says and then take them out. No no no no no. All ovens and recipes and baking pans are different, so one recipe time (suggestion) does not fit all. Here's what you do:
Set the timer for 5 minutes less than the recipe suggests.
When the timer goes off, start checking the cakes every 2-3 minutes according to the following:
If you tap the pan, does the middle jiggle? If yes, set the timer for 3 more minutes then check for jiggle again. If no, move on to step 2.
Are the sides pulling away from the pan? If no, set the timer for 2 more minutes then check again. If yes, move on to step 3.
If you tap the center of the cake layer gently, does it sound squishy, or does it spring back a bit? If squishy, set the timer for 2 more minutes then check again. If springy, AND the sides are pulling away from the pan, they're done! Take them out!
For reference, here's what "pulling away from the sides" looks like - these are examples of layers that are done. It's okay if they're browner around the edges than in the middle, and it's okay if they're domed a little in the middle. As long as they're not squishy and they're somewhat firm and spring back, they'll settle down as the cake cools.
For most butter-cake layers, cool them in the pans for 10 minutes then turn them out and cool the rest of the way. If you used cake goop they should turn out SUPER easily! If you turn them out top side down (of course), it's best to turn them over once again and let the side that was in the bottom of the pan be the side that's sitting on the cooling rack. The top side is often softer and if left to cool pressing on the cooling rack, can sometimes get sticky and come apart when they're done.
One more tip - once they're cooled to room temperature, if you wrap them well in plastic wrap (one at a time) and chill them in the fridge for a few hours, or even freeze them, they're MUCH easier to level with a bread knife and fill & frost. Happy Baking!