happym19,
1) this challah recipe is very soft. That’s why I recommend using oil and not flour if the dough is a little sticky when braiding it.
2) I usually divide the dough into 4 and from there make whatever size challos I need. Each of the 4 sections can make a large, 2 mediums, 3 smalls, or 8 bilkelach – or just divide it however you like. (When I’m lazy, I make a quater of the batch in the bread machine – use 7 1/3 Cups flour.)
3) Sorry I left out the 350. Length of time is estimated; you have to check the bottom to see if it’s ready. I don’t like when it gets overdone because I often freeze challah ahead of time.
I forgot to mention the egg wash. I use about 3 egg yolks diluted with a little water and about 3 teaspoons of sugar. (My family likes a sweet crust.
Enjoy!