In a bowl, mix yeast, one cup water, and two teaspoons sugar and set aside to proof.

Once proofed, add remaining water and sugar, eggs, oil, and salt and start mixing. (This can be done by hand or in a mixer; currently, I use a Bosch, but for years I did this by hand.)

Very slowly start adding the flour, pouring it in bit by bit and watching carefully. Once the dough comes together (i.e., the sides of the bowl are clean), stop adding flour. Sometimes I don’t use the whole bag; it depends on the weather and the humidity.

Cover and let rise until triple in size, about two hours.

Divide the dough into six equal parts and shape each one into a long, thin rope. Wrap it around, creating a turban-like look.

Smear with beaten egg and top with sesame seeds.

Bake at 350 degrees Fahrenheit for 30 minutes for lighter-colored challah or 40–45 minutes for darker challah.