To Make the Dough:

In a large bowl whisk together the flour, salt, sugar and instant yeast.

In a medium bowl or a large measuring cup, combine the buttermilk, the boiling water, and 1/2 c of water. Stir to combine, then add to the large bowl with the dry ingredients. Stir well and add the melted butter. Mix until the liquid is absorbed and the mixture forms a sticky dough ball.

Cover the bowl with a damp kitchen towel or  plastic wrap and set aside in a warm spot to rise until the dough has doubled in bulk, about 1.5 hours.

Grease two 8.5 by 4.5 inch loaf pans generously with butter. Using two forks, deflate the dough by releasing it from the sides of the bowl and pulling it toward the center. Rotate the bowl in quarter turns as you deflate, turning the dough into a rough ball.

Dust a clean work surface with flour. Using the two forks and working them from the center out, seperate the dough into two equal pieces. use the forks to lift one portion of the dough onto the clean surface. Using as much flour as necessary, dust your hands and the exterior of the dough and shape the mass into a ball. Repeat with the other half and allow both to rest without touching for 20 minutes.

Preheat the oven to 375.

Dust another surface with flour. Transfer one round to the surface and gently stretch it into a rough 10 by 15″ rectangle.

In a small bowl, combine the cinnamon and sugar. Brush the dough with the egg wash. Sprinkle the dough with half of the cinnamon sugar mixture. Beginning with the short end, roll it tightly into a coil and place into greased loaf pan. Repeat with the other round. Do not cover the pans. Let them rise in a warm counter area for about 10 minutes or until the top of the dough just crowns the rim of the pan.

Transfer the pans to the oven and bake until the tops are golden brown and firm to the touch, about 40 to 45 minutes. Remove the loaves from the oven, carefully turn them out onto a cooling rack and cool on their sides for 20 minutes before slicing.