I think it's interesting how "delicious cake" has branched off into several different sub-meanings: there's the literal "it is delicious cake, you must eat it" (and the more general "it is adjective noun, you must verb it" that derived from this); the MS Paint "puzzle" with dots representing "you" and "delicious cake", which intermingled with "the cake is a lie" from Portal after it came out; and thirdly, the abstract "cake" == "loli". I seem to have missed the birth of the third, but I imagine it started off as a transposition of "loli" for "cake" in one of the aforementioned puzzles, perhaps also inspired by that song from Lazy Town.