DC annual

[JayzusB.Christ]

Does anyone remember this annual? Published some time in the early 80's I think; I got it for my 9th birthday or something.
The best story was a Batman one - possibly by Alan Moore? Anyway it was about the Joker trapping Batman in a 'Rumpus Room' in an ice-cream factory; with a samurai jack-in-the-box and a load of dangerous robot toys.
There was another story with Superman and Mr Mxyzptlx and one about the Atom planning to reveal his true identity.