Last year, I made a mega Jaffa cake for my OH, to celebrate something or the other. It was a sponge base, topped with orange jelly, and a very firm chocolate ganache on top. Erm,...... Why did I feel the need to describe a Jaffa Cake?!??
Anyway, with your culinary skills, I bet you could recreate that in a low carb way, if you set your mind to it. The secret for the original was ensuring the ganache was cool enough not to melt the orange jelly, or it went rather slithery. Don't ask exactly how I know this. If you want, I'll trawl for the recipe, but probably not required.