An apple pie is a fruit pie in which the principal filling ingredient is apple. It is, on occasion, served with whipped cream or ice cream on top, or alongside cheddar cheese. The pastry is generally used top-and-bottom, making it a double-crust pie; the upper crust may be a circular or a pastry lattice woven of crosswise strips. Exceptions are deep-dish apple pie, with a top crust only, and open-face Tarte Tatin