An apple pie is a pie in which the principal filling is apples. Apple pie is often served with whipped cream, ice cream, custard or cheddar cheese. It is generally double-crusted, with pastry both above and below the filling; the upper crust may be solid or latticed. The bottom crust may be baked separately to prevent it from getting soggy. Tarte Tatin is baked with the crust on top, but served with it on the bottom.