Ersatz jelly donut -- cheap, easy and quick.
I always want donuts at about 8 PM -- when there's not a fresh donut to be found anywhere.
Hence, my ersatz jelly donut recipe:
Butter a slice of bread. Add a glop of raspberry jam in the middle. Fold in half over the jam. Powder the outside with powdered sugar.
Quite a satisfactory substitute for the real thing. Feel free to choose the bread, use a different filling, and, if you must, omit the powdered sugar (but it won't be as satisfying).
EDIT: A couple commenters have mentioned alternatives requiring frying. That's all well and good, but decreases how easy my method is. Do what you prefer and enjoy!