Yes, coconut sugar, or granulated coconut nectar. Pure Cacao + Granulated Coco Nectar. Our (fair trade) producer has been making them since 2009. They are wonderful!
Remember, as far as the human body metabolism goes, sugar is sugar. if you're marketing directly for a diabetic market, please be sure you understand the impact of glycemic index and sugars (pretty much any of the pentoses and hexoses - such as sucrose) will impact insulin levels regardless of if it comes from cane, beet, coconuts, or maple trees. The body will see no difference between sugar in the raw, granulated white sugar, cane sugar, beet sugar, etc. High potency sweeteners such as stevia, are an entirely different class of compounds, and as such, the body metabolizes them differently. Lots of info here on these topics already, i'd encourage you to sift through the forums.
Here's a good place to start: http://chocolatetalk.proboards.com/thread/391
yeah we are producing chocolates sweetened with coconut sugar 60% & 70% Chocolate bars plain & spicy.