Delicious Cake is a minor anomalous level in Super Mario 64. You enter into the level through another minor anomalous area that looks very similar to Peach's Castle. There is no obstacles or other objectives other than recieving the star above the cake. Appearance of this level will signify signifigant anomalous happenings afterwards. There is only a single video documenting the level.
When you enter into the level for the first time, you are greeted with a message from Princess Peach.
"Oh Mario! I am so glad to see you! I baked this cake for us to eat!
There's a problem... I'm stuck inside the walls.
Mario, you have to save us from that Koopa King!
I am channeling all of my star energy just to talk to you Mario...
Please take the star atop the cake!
Hopefully it will help you on your journey... Good luck Mario!"
The level only consists of a large wooden plane, and a large model of a cake with a small (presumably) cherry on the top. A ring of coins surround the cherry and a star floats above it. Once Mario collects the star the game proceeds to crash and there are several possible anomalous effects that can occur afterwards.
This level may have originally been intended to be a part of a beta prologue, where this level would be why Mario goes to Peach's Castle, as opposed to the letter from the final version.