Crumbs Organic Bakehouse is located in Ascot Vale, if you need to google it. I've never been there, and I don't know if they sell direct to the public, but I do know that they stock the cake displays at both Friends of the Earth and TOFWD.
During Worldcon I brought some friends across to DeGraves Lane in order to introduce them to the wonders of cakes as provided by Crumbs. I love this chocolate and sour cherry cake most of all: it is usually moist and rich and super delicious. They also do a citrus cake, and a tropical cake, and all three of these cakes are gluten-free and vegan. They are expensive pieces of cake, but they are totally worth it!
If you are looking for a nice piece of cake, I definitely recommend the cakes provided by Crumbs. They are good. Very Good.