Cake is about finding out that however lofty your ideals maybe, you can always be wrong.
This comedy, as all good Hollywood productions, starts by over doing the traits of its main character. At some point, her zealousness runs her into a wall and then the movie starts to be a bit more realistic, a bit more sensible.
The story itself is simple, the plot elements unsurprising, and, even if the dialogs hold their own and are funny, they are uninventive.
The big attraction of the movie is that it is entertaining, and it doesn't screw up. You'll spend a good evening if you're interested in seeing an over idealistic, over energized young woman make a mess of things and then save the day in true Hollywood fashion.