Instructions

1. In large bowl (I use a stand mixer) add the sourdough starter, pumpkin puree, milk, and eggs. Mix on low until just mixed.
2.  In separate small bowl, mix the 3 1/2 cups flour, sugar, pumpkin pie spice, and cinnamon.
3.  Return the mixer to the lowest settling, slowly add the flour mixture, gradually adding up to 1/2 cup more if needed until just combined. Allow the dough to rest for about 20 minutes.
4. After the dough has rested, add the butter about a teaspoon at a time mixing on low. Mix on high for about 10 minutes (or 10-15 minutes if you are needing by hand) or until the dough has passed the window pane test (see notes). This will be a sticky dough, do resite the urge to add additional flour.
5. Put the dough in a large greased bowl and cover with a damp towel or plastic wrap. Leave it on the counter to rise until doubled in size. This can take 6-12 hours.
6. Once the dough has doubled in size, sprinkle the counter with flour. Punch the dough down and turn the dough out onto the counter. Gently roll the dough out until it is about 1/4 inch thick, making a rectangle that is about 12 by 8 inches. 
7. Now make the filling, mix the soft butter, vanilla extract, sugar, cinnamon, and pumpkin pie spice. Spread evenly over the dough.
8. Starting at the top of the dough, tightly roll towards the front of the counter. Gently mark the dough to make about 12-15 equal parts depending on what size cinnamon rolls you want. Cut the dough with a sharp knife.
9. Grease or line a baking dish. I use a 9" by 13" glass baking dish. You can also use a large cast iron skillet or a half baking sheet. Place the rolls tightly together for pull apart rolls or space them further apart for stand alone rolls.
10. Cover with the pan and allow to rise 2-3 hours on the counter or overnight in the fridge.
11. When you are ready to bake preheat the oven to 350F. Once the oven has come to temperature place the rolls uncovered in the oven. Bake for 35 to 30 minutes. You want the internal temperature of the dough to be 190-200F.
12. While the rolls are baking, if you are making frosting, add the softened butter, powdered sugar, vanilla extract, and cinnamon to a medium bowl. Mix on high with a handheld mixer until fluffy. Set aside to frost the cinnamon rolls once cooled.
13. Eat them hot out of the oven as is, make a drizzle, or allow to cool and whip up a simple vanilla icing to top the rolls with.