18. Preheat oven to 350 degrees F. Bring 4 quarts of water to boil in a oval saucepan or roasting pan on your stovetop. The pan should be large enough to immerse the rolls in batches. Dissolve the baking soda and 1/2 cup brown sugar into the boiling water, using a whisk to break up the baking soda and sugar that settles on the bottom of the pan. Careful, the baking soda will fizz up when you add it to the boiling water!
Bring the cookie sheet to the stove area. Gently immerse the mini braids in the boiling water for 30 seconds. Turn them once with a spatula to make sure both sides of the braid are evenly moistened by the boiling water. Use the slotted spoon to carefully remove the braids from the water and place them on the kitchen towel lined cookie sheet. Water Bath Done – Final Phase!
Let the soaked braids rest on the kitchen towel for a few minutes while you prepare your egg wash. They will look slightly "water-logged" and pruny at this point, but don't worry, they'll puff up again when they bake. The kitchen towel will soak up any excess liquid so the bottom of each mini challah doesn't become soggy.
To prepare the egg wash, whisk together the yolk, water, sugar and salt till smooth.
Gently remove the mini challahs from the baking sheet by slowly pulling the kitchen towel off of the cookie sheet. Lay down parchment and sprinkle with a light dusting of cornmeal. Pretzel bread is sticky business; doubling up with parchment paper and cornmeal is the safest bet to ensure that the mini challahs don't stick.
Place the mini braided challahs onto the parchment paper lined baking sheet(s).
Brush the challahs evenly with a light, thorough coating of the egg wash.
Dust the challahs with kosher or coarse salt to taste. Careful, they can get very salty very fast! A thin, even sprinkling will work best.
The challah needs to bake for about 15-18 minutes total.
Mini Pretzel Challah is finished when it's a dark golden brown color all over. Test the mini bread for doneness by turning it over and tapping on the bottom of the loaf—if it makes a hollow sound, it’s done.
To keep the outer part of the pretzel challah soft and supple, you can brush each challah with a tablespoon of melted butter or margarine as soon as it comes out of the oven (if you use butter, it becomes a dairy dish, not pareve). This step is optional.
Let challah cool slightly on the baking sheet or a wire cooling rack before serving. Pretzel challah is best served warm; reheat before serving. Store it wrapped tightly in plastic wrap or foil to keep it fresh.