I think you may have been following the thread "Has anyone made a cake?". I posted an icing reicpe there that I plan to use on a diabetic cake this weekend. It has no sugars, very few carbs and is made with granular Splenda. Despite all that, it tastes pretty much like regular icing.
The cake is as yet not determined, but I have the Splenda Chocolate Cake that becca0926 sent the link for in the oven as we speak.
It is even rising! Tthe last four cakes I tried did not do that well at all.
Aunt Judy posted a really yummy sounding chocolate ganache icing too.
The back of the Splenda for baking bag has a recipe for yellow cake. If the chocolate one works, my mehtod for lemon cake would be to use the yellow recipe and add lemon extract. I'll let you know how the chocolate cake works for me, but I'm doing a non-dairy version, so your mileage may vary, as they say.
Aunt Judy, I agaree that, where possible, it is better to have a bit of something really good that is real, than something that is fake and only so-so. I continue the quest for real and wonderful and low-sugar. If this cake doesn't work, my next try is the chocolate mousse cake in The Cake Bible. It has only three ingredients: chocolate butter, and eggs. I would try to use chocolate sweetened with mannitol along with some unsweetened chocolate and see if that worked. If I get to where I'm making that, I'll let you know. While my icing is high fat, it doesn't have any more fat than normal icing--just less sugar. While Mannitol can have it's own consequences, I am keeping it to a minimum, adding unsweetened chocolate and coming up with a less sweet icing, which is what most people want, anyway. I too love choux paste--better than cake, even. Not everyone agrees, alas, and so we still have people who want decorated cakes. Come to think of it, that's a good thing! haha!
It's several hours later and I baked and leveled and tasted the the Splenda for Baking Chocoalte cake and it was a complete success. I will be using it for my friend's Dad's birthday cake this weekend. Thanks to Becca0926.