Challah — perhaps the most delicious bread in the world. It’s almost a cake and has the calories to prove it. It’s the traditional bread of Shabbos and Jewish holidays. Yes, it can put 10 pounds on you in a flash, but it’s so good, who cares?
In a medium-sized bowl, dissolve the yeast and sugar in 2 cups of the warm water, cover loosely with a towel, and set aside. Place the salt in an extra large plastic bowl.
Add the flour to the bowl, then the sugar and egg yolks. The yeast should now have bubbled/foamed and doubled in size; if not, repeat the process again.
Make a well in the middle of the flour mixture and slowly pour the yeast and sugar-water mixture into the well. Then, add the remaining 4 cups of warm water into the well. (Make sure the water is not too hot. It should be no warmer than you would use for a baby’s bath.)
Start kneading the ingredients together and add ½ cup of the oil. For the next 10 minutes, knead, adding another ½ cup of the oil slowly as needed to create a workable dough. (The dough shouldn’t be too sticky and also should not be dry. It should become 1 cohesive mass.)
Loosely cover the dough with a large kitchen towel and place in a warm spot in the kitchen for 15 minutes. After 15 minutes, lightly oil your hand and knead again for 5 more minutes, adding a touch more oil to the dough if necessary. (The dough should now be easier to work with and will become smooth and satiny.)
Rub a little oil over the top and around the dough. Cover the bowl with a kitchen towel. Place the covered bowl in a medium-sized plastic bag and place the open ends of the bag loosely underneath the bowl, trapping in air.
Place in a warm spot and let rise for 1 hour or until doubled in size. Punch the dough down and knead (lightly oil your hands if necessary), flipping it and releasing any air bubbles. Cover again, using the towel and the bag, and let rise 1 more hour.
Lightly oil your hands, and punch down again. With a sharp knife divide the dough into 4 equal parts. Liberally spray four 9-inch round baking pans with cooking spray and set aside.
Preheat the oven to 375 degrees.
With lightly oiled hands, place 1 piece of dough on a smooth work surface. Play with the dough a bit, squeezing out any air bubbles. Separate into 8 equal parts. Roll each part into a round ball, adding oil as needed to keep it from being too sticky. (Don’t use too much oil; a little sticky is fine.)
Place 1 ball in the middle of 1 of the pans and surround with the remaining balls. (Don’t worry if they don’t touch. They will rise into each other while baking.) Set aside. Repeat with the remaining dough so that you have 4 challahs.
Brush the challahs with beaten egg and top with a combination of the sesame and poppy seeds. Bake for 10 minutes and then reduce the oven temperature to 350 degrees and bake until the challah tops are dark golden brown, about 35-45 more minutes.
Remove from the oven and let cool slightly before serving. Serve while still warm. Once the challah has been sliced, you can store the slices in sealable plastic bags for about 4-5 days.