If I have found that a cake is undercooked after it is baked, can it be put back in the oven? My cake tester came out clean, but the cake sank in the middle & seems very moist on the bottom.
Think about how a cake bakes in the first place. You put the pan in the hot oven, and what does the heat first encounter? That's right, the outside of the cake the top, the bottom, and the sides. As the cakes sits in the oven, the heat is gradually transferred from the outside portions to the center, and when the center is done, you remove the cake and put it on a cooling rack. The whole process has been an exercise in cooking the center without overcooking the edges.
Now you are thinking about starting the process all over. What is going to happen? The heat will contact the outside of the cake, and by the time it works its way to the
center again, the outside will be so overdone that you might as well cut it up and use it for croutons.
In practical terms, there's not a whole lot you can do. If it just came out of the oven, you can certainly put it back in. But if it has cooled even a bit, you risk overcooking the
edges, top, and bottom. The best bet may be to cut or scoop out the gooey center, pretend you intended to make a
tube cake in the first place, and fill the void with fruit and/or whipped cream.