I think that would count as a straightforward belief on Rolf's view, because you can test it empirically. We have to qualify that by saying you 'can in principle', since testing for that (especially a chocolate cake) would be impractical, but that's no problem for the meaningfulness criterion.
Which of course invites the question of whether I believe I can test it empirically.
Alternatively, one could ask whether I believe that a piece of chocolate cake didn't spontaneously materialize in the asteroid belt at 2:15pm EST on April 11 2012 and float there for fifteen minutes before dematerializing... unless we want to say that the fact that I could have tested it last year counts as "can test it in principle." Which I suppose is no sillier than anything else.
Regardless, I'm more interested in the second question. On Rolf's view, why do...
Very brief recap: The logical positivists said "All truths are experimentally testable". Their critics responded: "If that's true, how did you experimentally test it? And if it's not true, who cares?" Which is a fair criticism. Logical positivism pretty much collapsed as a philosophical position. But it seems to me that a very slight rephrasing might have saved it: "All _beliefs_ are experimentally testable". For if the critic makes the same adjustment, asking "Is that a belief, and if so -" you can interrupt him and say, "No, that's not a belief, that's a definition of what it means to say 'I believe X'."
A definition is not true or false, it is useful or not useful. Why is this definition useful? Because it allows us to distinguish between two classes of declarative statements; the ones that are actual beliefs, and the ones that have the grammatical form of beliefs but are empty of meaningful belief-content.
It seems to me, then, that both the positivists and their critics fell into the trap of confusing 'belief' and 'truth', and that carefully making this distinction might have saved positivism from considerable undeserved mockery.