Set a medium/large saucepan over medium heat and add Milk (3/4 cup). Heat until steaming but not boiling. Add the Unsalted Butter (1/4 cup), stir, and let the mixture cool to lukewarm. Once lukewarm, stir in Instant Dry Yeast (17 gram), Granulated Sugar (1 tablespoon), Ground Cinnamon (1 tablespoon), Sweet Potato (1/2 cup) and Egg (2). Add 2 cups of the All-Purpose Flour (5/2 cup), stirring to combine, then cover with a warm damp cloth. Set in a warm place to rise for 1 hour.
After an hour, add remaining ½ cup of flour, Baking Soda (1/4 teaspoon), Baking Powder (1/4 teaspoon), and Salt (1/4 teaspoon). Transfer to a well-floured surface and knead until smooth and no longer sticky (you can add up to ½ cup more flour if needed). Roll dough out into a large, ¼ inch-thick rectangle.