I know this will sound like a cheap plug, but I've actually done something similar to this and I've used my own chocolate protein powder and extra egg(s) to help bind it all. The protein powder plus almond meal helps achieve flour-like consistency and really holds together well.
Basically the Worker Bees and I have played around with variations on this recipe:
and have found Responsibly Slim to be a tasty and helpful addition. The vanilla powder works well with nut and fruit bars. Chocolate would be perfect for your needs.
I'd be interested to hear other ideas from forum members. If you've tried something like this chime in with your thoughts and experiences!
Also, check back next week. If things go according to plans I'll be bringing you a Primal ice cream dessert recipe. (If not ice cream some other cool treat.)