This is one of those cake shop treats we're all familiar with - I'm sure it's European in origin, but has found a place in the hearts & stomachs of Australians for generations. As for the name game, I grew up in New South Wales & have always known it as a Vanilla Slice & I remember the name 'Snot Block' from school... but can't claim to have heard it used by any adults in my circle, myself included
This sort of leads me on to the related topic of names you grow out of using... or should grow out of, anyway. 'Snot Block' is amusing to kids between the age of 6 - 16, let's arbitrarily say... but is it really that funny when anyone over the age of, say 25, uses it? What other names for things do you remember using as a child, that you don't use any more?