Very good but didn't rise. Recommendations?

I'm not a big fan of slouching, dense cakes. If I were ever to make a cake like this, I'd separate the eggs and fold in the stiffly beaten whites at the end. (In fact, I'll be posting the recipe for such a cake in the next month or so.) I realize that some would say I totally miss the point -- people expect and want flourless cakes to be dense and fudgy, and frankly, a flourless chocolate cake ultimately is sort of like fudge, baked -- so I couldn't disagree. ;o)

flourless cakes have almost no flour, so they don't rise much. yours looks like it should imo. You might want to do a 52 Search under Recipes for "flourless" and also do google image for same- so you can see how they look.