High-Altitude Egg Challah

Combine sugar and yeast in a measuring cup filled with warm water. Allow the mixture to sit for 5-10 minutes, or until it becomes frothy and bubbly.

In a separate bowl, whisk together eggs. In another measuring cup, combine the egg yolks and enough milk to create a total volume of 1/3 cup (including the yolk). Gradually add this mixture to the beaten eggs, stirring until well combined. Next, incorporate the yeast mixture, melted butter, salt, and an additional 2 tablespoons plus 2 1/2 teaspoons of sugar into the egg mixture. Finally, gradually incorporate flour until the dough reaches a suitable consistency to handle.

Transfer the dough onto a floured surface and knead until it no longer sticks to your hands. You may need to add more flour during this process. Place the dough in a lightly-oiled, large bowl and coat it evenly with oil. Cover the bowl with plastic wrap and let the dough rise until it has doubled in volume, approximately 1 hour.

Divide the dough into 3 or 4 equal portions and shape each portion into a long rope. Braid the ropes together, tucking the ends under to create a neat loaf shape. Place the loaf on a baking sheet and cover it loosely with plastic wrap. Allow the dough to rise in a warm environment until it is ready for baking, which can be determined by pressing your finger into the dough - if it leaves an impression, it's time to bake.

Preheat the oven to 350 degrees F (175 degrees C).

In a small cup, whisk together the remaining egg with a fork. Brush this mixture onto the loaf to give it a golden color and crispy crust.

Bake the bread in the preheated oven until it is golden brown and sounds hollow when tapped on the bottom, approximately 35 minutes. Remove the bread from the oven and transfer it to a wire rack to cool.