• Make the Dough
• In a medium bowl, combine the flours, sugar, dry milk powder and yeast.
• Heat milk to 75°F-85°F. Pour into a large bowl and whisk in the egg and sourdough discard. Mix well.
• Add the flour mixture to the milk mixture and mix with one hand until all the flour is incorporated. Cover and let sit for 20 minutes.
• Add the salt and melted butter to the dough and mix well.
• Fold over knead 20 times and let rest covered 15 minutes.
• Fold over knead 20 times and let rest covered 15 minutes.
• Fold over knead 20 times and let rest covered 15 minutes.
• Fold over knead 20 times.
• Place dough into an oiled rising container, cover and let rise until doubled. (1½-2 hours.)

Assemble the rolls

• When the dough has doubled roll out to a 12-inch by 16-inch rectangle.
• Mix the cinnamon filling and melt the butter.
• Leaving a ½-inch border around the dough, brush the rectangle with melted butter and sprinkle on sugar mixture.
• Note: 2/3 cup raisins and 1/2 cup toasted walnuts or pecan may be added here. Soak raisins for 20 minutes in hot water, drain well and cool. Toast the nuts in a 325°F oven for 8 minutes or until fragrant. Cool. Sprinkle evenly over cinnamon butter.
• Starting at the long side, roll the dough into a tight cylinder, pinching tightly to seal the seam.
• Cut the dough into 12 pieces andplace cut side up, into an oiled 9" by 12" baking pan. For easier removal of rolls and clean up, line the pan with parchment paper.
• Cover the rolls with plastic and let rise until doubled, 1-1½ hours.
• Adjust an oven rack to the middle position. Preheat the oven to 350°F (180°C). Remove the plastic and bake until the rolls are golden brown, about 30 minutes. (195°F internal temperature)
• When rolls are finished baking, transfer to a wire rack and brush immediately with ½ of the icing.
• Let cool for 30 minutes and add the remaining icing. (If desired.)