Wikipedia user Justinc
It’s an English dessert. From Wikipedia:
Spotted dick (also known as “spotted dog” or “railway cake”) is a traditional British steamed pudding, historically made with suet and dried fruit (usually currants or raisins) and often served with custard.
“Spotted” is a clear reference to the dried fruit in the pudding (which resemble spots). “Dick” and “dog” were dialectal terms widely used for pudding, from the same etymology as “dough”
Why I Looked It Up
On an episode of Just Shoot Me, Jack gets back from London and talks about how much he loved “Spotted Dick,” much to the amusement of Dennis.