Question: where are all the different birthday cakes?
Answer: Junk Junction - Right in the centre.
Loot Lake - On one of the small islands just to the north of Loot Lake.
Fatal Fields - Right in the centre.
Salty Springs - Right in the centre.
Lonely Lodge - North of Lonely Lodge.
Shifty Shafts - Near the centre, at the entrance to the shafts, close to a reboot van.