Briaded Portuguese Easter bread
I assume you mean the sweet bread with eggs 'folar de pascoa' which isn't really a braided bread like a challah (its often decorated with braids over the eggs though)? Central Bakery in Cambridge bakes the most in the immediate area and you can purchase a variety of sizes sized by the number of eggs and for some sizes the eggs are more pressed in than braided over. Depending on where you are located the Lowell Portuguese Bakery and Central Bakery in Peabody also have versions. As well as Winter Hill Bakery in Somerville which should have a version (and I prefer to Central for some things), but haven't tried it.
Winter Hill Bakery
318 Broadway, Somerville, MA
Hanneford's in Waltham had portuguese sweet bread from some place on the South Coast this weekend. My wife who is from the Fall River area was shocked (and excited) to see it. No eggs though. I did remember seeing some braided bread with eggs in them, but didn't pay attention to what kind of bread.