I have a recipe for a pineapple walnut cake and everytime I bake it the pans sink in the middle close to end of baking time...any idea why? They look wonderful and high up until the last 15 mins or so. Thanks for your input.
Basic recipe: sugar, flour, baking soda, pineapple w/juice, eggs, nuts
In order to help with the recipe we need quantities of each ingredient plus the process of how you mixed it.
What you stated in the ingredient list is pretty much what is any cake recipe, except for the pineapple. So that list is not good without the rest of the information.
More than likely you have too much liquid and/or oven too hot.
Actually you can have a cake sink from too little liquid also. I have just spent months making my cake formula all sorts of ways.
Too little liquid will also make a cake fall, as well as too much moisture, among other things. Mainly the recipe has to be balanced in order to behave well. You can get a cake from an unbalanced recipe and probably a pretty darn good tasting on too. But if you don't want a cave in the middle, it has to be balanced. There is a fine line.
That is why I said you need to post the recipe. And in all my testing I have never found too hot an oven to be an issue ever, even when testing up to 400 degrees. A cake will actually bake hard into a hockey puck before it will sink in the middle. If you google "cake sinking in the middle", the two reasons above come up time after time as the reason why. Those two answer are not the only things that can cause a cake to sink. But keep digging and you will also find that some sites say not enough liquid will cause a cake to sink also. I was experimenting with my cupcakes and put half the liquid that I usually do and got sunken cupcakes. Once I added back in the amount of liquid I usually use they did not sink. I will say it again, they only sunk because I put in less liquid, not more.
I have found that the reason why cakes and cupcakes sink are numerous. They could be any one of these reasons: underbaked, not enough liquid, too much leavening, too much sugar, and too much liquid (way too much. You would know before you even bake. A scratch batter would be very liquidy). If they sink after they come out of the oven it is underbaked. If they sink before they come out of the oven it can be not enough liquid, or too much liquid, too much leavener, or too much sugar.
Your recipe may not have compensated for the sweetness factor in the pineapple or you used pineapple that had sweetener added to it. Too much sweetener in the pineapple coupled with the amount of sugar you put in will cause sinking.
If a cake has too much leavener not only will it fall, but the crumb will be very light, airy and fall apart in your hands. That is how you know you put too much leavening in a cake or cupcake and it is not the other reasons why it fell.
I have tried experimenting all these ways. Again post the amounts you added, then we can tell where it went wrong. Also your recipe does not state any more added liquid than the pineapple juice. So needing those amounts added is crucial in determining what went wrong.
Make your batter thicker by adding more flour. This will do it. I have the same problem with one cake recipe and made a note to myself to add an extra 1/2 cup flour to thicken the batter - and it comes out perfect each time.