Place yeast, water, and sugar in a large mixing bowl and stir to combine. Place in a warm spot until yeast is proofed and the mixture shows bubbles, approximately 10 minutes.

In a second large bowl or measuring cup, place four cups of boiling water. Add sugar and salt, and then stir until they are completely dissolved.

Sift the flour.

Add the flour to the bowl the with the yeast mixture. Add the water mixture, oil, and the desired amount of eggs. Mix and knead the dough well, approximately 10-15 minutes

Coat dough with one to two tablespoons of oil to prevent it from sticking. Cover with plastic wrap and allow dough to rest for a minimum of 45 minutes up to three hours.

Preheat oven to 350 degrees Fahrenheit.

Divide the dough into five pieces. Each piece will yield one loaf of challah. Further divide each piece into the desired amount of strands for braiding. If needed, add oil rather than flour at this point to make the strands. Braid the dough and place each loaf into well-oiled or sprayed pans.

Allow challah to rise until doubled, approximately one hour.

Combine the egg wash ingredients, making sure the egg is beaten well. Apply egg wash to the challah. Sprinkle with desired toppings.

Place challah into hot oven. Use a spray bottle to spray water into the hot oven to create steam. Repeat this step 10 minutes into baking.

The challah should bake for 45 minutes. After 30 minutes, rotate the pans so the challahs bake evenly. You can also reapply the egg wash during baking to those areas of dough that become exposed during baking. Upon removing challah, spray water to retain moisture. Immediately remove from pans and place on wire racks to cool.