Cafe Blossom is a surprisingly delicious vegan, kosher restaurant, with multiple related but slightly different chains around the city. The one on the Upper West Side, at least, has chocolate cake:
So we talked about problems with kosher chocolates, but there was some follow-up discussion that yielded a conclusion that the problem wasn't necessarily either the kosher stuff or the dairy-free stuff but rather the combination. But the conclusion was based on the idea that we Jews have not done as good a job as vegans have in making chocolatey, dairy-free desserts. But in this cake, we have not a dairy-free product made by people who keep kosher but rather kosher products made by vegans. This turns out much better.
So the floury cake part is going to be a problem. It's delicious but a little dry. But vegan chocolate mousse made by vegans is much better than regular kosher parve chocolate mousse. Cafe Blossom has done a great job using the mousse to mask a slightly dry cake, and the end product actually winds up totally great.
Bottom Line: For vegan food and vegan chocolate dessert to follow, Cafe Blossom is a really excellent option.