Hi. I need to make a cake for a contolled T2D - they will eat natural sugars - so I know the cake recipe, but I do not want to use fondant as it's made with glucose and sends their sugar levels soaring! They will eat buttercream, but as it's a novelty cake, I need to be able to pipe whatever icing I use and I'm not sure how to put b/c on a cake and get a really smooth effect - I'm thinking something to do with chocolate (as they will eat this in moderation). If you could give me some ideas/recipes as I'm not that experienced at baking! Thanks in advance.

Have you considered SMBC? It does not have as much sugar as other BC and is not as sweet. What I have heard is that it also pipes really well. I have never made it before but will give it a try as well as I am making my first diabetic cake in a few weeks.