La Boulangerie is a good French bakery. On Cedar and Barstow, Slice of Cake (I think that's what it is called) is own by a Viet. family. There is a small bakery on S.E. corner of Clinton and Fresno (next to a herbal shop) that makes decent cakes--I think they are called "Queen's Cake". It's light and not too sweet. They make a good coconut cake.
My suggestion is the Nicoise cake from La Boulangerie. It is a french cafe in Fig Garden Village. I ordered this for my SIL's 50th surprise party and it was excellent. They told me it is their top seller (beating out the chocolate cake which I hear is also very good.) De Bakkerjj is also good - I believe the owner is Dutch but I may be mistaken. But between the two, my vote goes to Boulangerie. I have tried Eddy's but honestly do not understand the attraction. Must be me though because they do a fairly brisk business.
I really enjoy Eddie's Bakery for pastries, cookies, and cakes. The cakes are moist and flavorful and they are very creative in their design. One year our office had Halloween cakes and they made the head of Frankenstein and also a pumpkin that looked real. Better yet, they tasted fantastic. The website, linked below, has pictures of what they can do.
As far as a Vietnamese bakery, the only one I really have seen would be the one at Cedar and Herndon right next door to the R and N Asisan Supermarket. Incidentally, the Asian market is quite extensive. The place next door, sorry I don't know the name, has French style baked goods, iirc. Maybe you could head over there and check it out.
There is an excellent European style bakery in town that makes terrific scones and breakfast pastries. They also make cakes, which I have seen but never tasted. They look absolutely stunning and since the pastries are so good, I can't imagine the cakes being bad tasting. The name of the bakery is De Bakkerij and the delightful husband and wife owners will be more than willing to help you decide what kind of cake you would like.
Eddie's Bakery and Cafe
7089 N Cedar Ave
Fresno, CA 93720
De Bakkerij Bakery
3009 West Bullard Avenue
Fresno, CA 93711
P.S. There used to be a Basque bakery on Inyo street a long time ago, but I have no idea if they are still there and still good.