Without knowing what cabin you're in ...

You have the cake option , for a fee now sadly , and then as Skywards Hunter said the champagne option if your in economy - in reality it may seem a good idea , but you might feel a bit silly when on the plane ( well I would imo). If you're in business and first class then no need to worry about champagne as you will get that for free. You also additionally have the option of the crew taking a photo of you , for free , with one of those instant photo printing cameras. A upgrade might be worth looking into if finances permit.