|Not remotely sugar-free cake|
Here is Miss Whiplash a cake blogger writing about this indulgence:
What is not in question, however, is that there is any difference at all, from the point of view of "health" (meaning, in this case, how it acts in and with your body) between sugar from-a-bag (as prohibited in the episode in question), sugar in honey, sugar from syrups/nectars and, indeed, sugar from fruit (or anywhere else). Substituting one of these things into your cake may make it taste better (and will almost certainly make it different), but will not make it any more or less acceptable from a physiological point of view to anyone - there is nobody for whom this cake will be a more "better" thing, unless they happen simply to like the taste (or have some kind of ethical reason for not eating sugar-from-a-bag, perhaps). It is a pointless (if not actually fruitless...) exercise.
There's a whole lot more on her blog. The point is important - this sort of anti-sugar message is misleading, unhelpful and, as Miss Whiplash points out as a T1 diabetic, potentially harmful. For me the most important point she makes is about how cutting out the sugar really misses the point:
Anyway, the point is that this cake would still be chock full of other carbohydrates (most commonly flour) which would, on eating, be turned to glucose extremely swiftly in the body, which would raise blood sugar levels almost as much as if it had been full of sugar in the first place.
And Miss Whiplash's 'sugar-from-a-bag-free' cake sounds good too!