As a former vegan, I found dining at WDW the easiest I'd ever experienced anywhere. At the table service restaurants, I included a notation in our reservation. At each restaurant, the chef came to speak to me personally about dining options; and I was amazed at all the delicious meals I experienced. Hands-down, my favorite was
Boma where I was actually made a HUGE vegan dessert. So rest assured, Disney chefs will do their best to make your experience memorable.
As for a birthday cake, they will also make specialized birthday cakes. You will need to call in advance: 407-827-2253 and make sure and share your dietary restrictions.
If you visit www.disneyfoodblog.com and do a search for
vegetarian, you will find a myriad of articles on specialized dining at WDW as well as one that is a link to www.allearsnet.com with a thorough chart of vegetarian/vegan dining choices. After reading the articles, I think you will have a great selection of food to choose from on your trip. Also, a search for
birthday treats will lead you to an article with a vast collection of photos of guests' birthday cakes, including vegan offerings.