An Album Cover = Anal Bum Cover. Catch These Men = Catch The Semen. Pen Island = Penisland.
Back when I was a kid I sometimes had to do (obviously kid-friendly) puzzles like this in the puzzle books Mom got me. One I remember was trying to find the animal word hidden in a sentence. As in, “On this hill I once sneezed” (lion).
They are arguably spoonerisms, though spoonerisms are supposed to be “accidentally humorous”. There is/was a guy traveling the renaissance faires who tells spoonerisms for a living. Zilch, the Tory Speller. He’s great fun to listen to.
Not by any usual definition of spoonerisms, which require parts of words to be switched in order. In the examples, all of the parts of the words are in order.
There was a website at one point where you could get expert advice on various topics, called “expertsexchange.com” I believe they eventually added a dash in the middle to avoid the ambiguity.
I enjoyed Derleth’s info on reanalysis. That said, I think I prefer to imagine that cheeseburgers come from the city of Cheeseburg, whose demographics largely resemble Hamburg, except for a lower rate of lactose intolerance.