In the Castle, there's a door found somewhere in the castle, it have a nutella icon. Most videos it don't appear, but rarely it does. Opening it (which needs to put a password, which is Nutella is good,) will lead to a blue room with stars. its similar to one of the rooms in SM64. The first time its seen, 7SMB7 is seen flying, saying he stole the nutella all the time, and that collecting the nutella will give him super-powers.