Just a reminder: if your birthday happens to fall within 3 days of your Turkish Airlines flight, you're entitled to a complimentary cake during the flight! All you need to do is call their office in advance (at least a day before departure) and let them know you'd like to enjoy something sweet. Full details about this offer here.

I've tested it myself — it really works. Delicious too. The flight attendants even sang "Happy Birthday" for me. The cake is huge, easily enough for two or three people.