Depending where in east bay, but Masse's bakery on Shattuck in berkeley (it's by the Longs Drugs across the street from Safeway (shattack and rose, but it's closer to the street south of rose)
Also in Berkeley (though nearer Oakland) there's La flourin (no clue on the spelling here) the two shops are the only 2 french bakerys that I know in the area. The style is different, I like the look of the cakes at Masse's better, but the cakes at La Flourin have a more traditional look to them. Oh, La Flourin is on College Ave. near the safeway on College and Claremont (this one's north of the safeway, but across the street)
I like Masse's better, but it might just be because I lived closer to there and went there more often (and before I went to La Flourin)
adding links
masse's (there's an official website that's pretty empty, but here's a review)
La Farine whoops, it's in Oakland and i totally mispelled the name.