What can I replace pineapple with in a cherry dump cake?
Any canned Apple Pie Filling (such as the Duncan Hines) would provide a similar flavor and texture to the pineapple you want to replace. You might want to mix in some apple juice (or cider) to the apple pie filling to thin out the liquid in order to get the right consistency and volume. 

Of course you will want to make sure you aren't simply replacing one allergen with another.