This is a difficult one, good Babka is hard to come by. Id check with epicure market (i think the deserts are insanely good and around passover they do alot of traditional jewish deserts, though mainly flourless). Kosher World on 41st has some good stuff. Its dingy but i love their rainbow cookies and suspect that they make a yummy babka. There are a couple of Jewish bakerys on 41st street, Ive been told to go to one that is east of Kosher world (closer to collins) but i cant recall the name.
Epicure Market for sure. I love that place.Their bake goods are phenominal. Their Babka's are very good too as well as their rugella. My sister-in-law swears their as good or better then any NY bakery. I use to routinely ship her up some and always brought a huge care package every time I visited my family up North from there. Once I even carried a whole cake on the plane from there. I have so many favorite things but its almost impossible not to get something good. Best to call the day before if you know you are going and specifically want a Babka. as everyday they don't always make them or if you get there in the afternoon, chance they will sell out. So if you call, they'll reserve one for you. Also, I prefer the whole Babka rather then the mini ones. As far as Passover, they do several differnt cakes as well. I always love their sponge loaf. It's just a great market and definitely worth visiting.
I think Epicure is so much better then Flakowitz. For me, I use to like Flakowitz years ago when they were in Lauderhill but now not so much. Expensive too.
I'm not Jewish and I'm not too familiar with Jewish pastries, but I did a taste comparison two years ago of the best sufganiyots from three or four places around North Miami Beach & Aventura area and the best I've had was from Sarah's Tent market at the Shoppes of the Waterways in Aventura.
In other words, I would probably suggest on calling Sarah's Tent to see if they make babka and get it there even though it's more of a market with a good bakery than just a bakery.. :)
I would probably give a call to see if they'll have Babka.
this might help:
also, if Boynton Beach isn't too much of a schlep for you, Guy Fieri featured a place on DDD called Flakowitz. i was pretty impressed by what i saw on the episode - maybe CHers who have been there can chime in with opinions...