well, now, if this isn't a challenge!!!
ok...first off, I searched internet & CC galleries, came up empty on any cakes.
found the really great pic of a fortune cookie (below) to use as guide.
ok..so you need 2 wonder mold cakes and a round that matches size of wonder molds when put together.
see sketch #1
split round, stack to make back
cut off part of wondermolds to get the flatter inside of cookie.
(if want more authentic, split remaing wonder mold in half and off set as in profile, sketch #2).
place two wonder molds against stacked half-rounds.
hit w/ BC to smooth out.
then -- if using crusting BC -- viva it
but, I'd use fondant so can get color and texture easier.
and don't forget a little strip of white fondant sticking out of one side w/ start of fortune on it.