Blueberry Muffin, can't go wrong with one of those.

Developers Favorite:
Order 2 Blueberry Muffins and 2 black coffees. Ask the waitress to melt some butter on top of the muffins then sprinkle on the sugar.
Drink both coffees and check email while you wait.
When the waitress delivers your blueberry muffins get your coffee refilled.
Eat both muffins and drink both coffees.
Pay, Tip and run back to your desk.