Add cooled scalded milk, 1/2 C water and sourdough starter to a large bowl and stir until starter is dissolved.
Add 4 cups flour to starter mixture until it is incorporated. Let sit for 30 minutes.
In a separate bowl, add sugar, oil, eggs, and salt. Mix until sugar dissolves and eggs are incorporated.
Add wet mixture to dough and mix until completely incorporated.
Add the last 3 cups of flour 1 cup at a time until all cups are incorporated. NOTE: I misspoke at this point, there are only 7 total cups of flour in this recipe, and an extra 1/2 cup that I sprinkle of my counter to knead the dough on.
Sprinkle 1/2 C flour on counter and knead dough for several minutes (3-5 mins).
Oil a large bowl and place dough in to rest. Cover and allow to rest for 30 minutes.
Stretch and fold dough 4 times, cover dough, and allow to rest for 60 minutes. Repeat step 8 two more times.
Put dough in refrigerator overnight, or at least 10-12 hours to ferment.
Take dough out of the fridge and leave it on the counter to proof for 2-3 hours or longer depending on the warmth of your house.
Flour counter, cut dough in half, and roll out dough. Generously spread softened butter on top of dough. Then sprinkle with brown sugar and cinnamon.
Roll the dough tightly into a log. Cut cinnamon rolls into 2 inch wheels. Place rolls in buttered 9x13 baking dish. Cover rolls and allow to rise for 2 hours.
Bake rolls for 25-30 mins at 375 degrees.