This is a traditional sweets bakery, but they cater to a range of special diets. Online you can view some of their dairy-free, gluten-free, vegan (etc.) options, but it sounds as if they can do custom orders too.
Location: 278 87th St. (Between 3rd & Ridge Blvd), Brooklyn, NY 11209
From their website, "We offer delivery in Manhattan, parts of Brooklyn, and we ship select items anywhere in the U.S."