Thank you for all the feedback. -
About the 'munchkins':
Thank you, for pointing out there role in 'The wizard of Oz' with the unforgotten Judy Garland, i.e. the Mother of Liza Minelli.
I see the ending '-kin' like the German ending '-chen' (or -lein) for the 'Diminutive' (Verkleinerungsform) like in Weibchen, Männchen etc. as used for the famous 'Mannekin Piss' in Brussels.
I figure, that 'munchkin' comes from 'munching' (related to 'chewing'), meaning a child (or, more generally, a small person, i.e. a dwarf [Zwerg] or Pygmy) that is munching (something) for the whole or at least, some sort of time.
About the meaning of it:
When computers were still 'fed' by 'punched cards' (Lochkarten), there were those bits of paper resulting from punching a number or character into a 'Punched Card' (also referred to as 'IBM-card', more correctly a 'Hollerith-card')
In Berlin, at the TU-Berlin, I learned from Mr. Kaiser at the time being (1970-1971), that he referred to those bits (or 'Schnipsel') as 'negative holes' (with the definition of a hole being "A 'nothing' with something around it" [Brecht or Morgenstern or Ringelnatz]
On the 'Kreppel' bit:
Sorry for mistaking Hesse(n) for Bavaria(?) but what I meant is, that anybody from any region within the reach of the German language is cordially invited to post his/her local (or better: regional) version of 'Fettgebäck', along with a short descripton of it.
'Schmalzgebäck', of course, would have to take second place to 'Fettgebäck', as some people (in not-any-more post-war-times use coconut-fat or -oil [like 'Palmin' (solid or fluid)] to bake their Berliners/Pfannkuchen/Krapfen/Kreppel/Küachle/Kichelche/etc/etc/etc in.
Also, I missed to include that version which is based on potatoe-flour (i.e. 'Kartoffel-Mehl) [was it Studnut?] - I'm sure, somebody (up there) will be able to sort it out and put it in line with my suggested classification-system...