Add 2 cups (248g) flour, sugar, dry yeast, and salt in the bowl of a stand mixer fitted with the dough hook. Whisk to combine.
Place milk and butter in a microwave-safe measuring cup. Heat, in 30 second increments, until the water reaches 120°-130°F (think hot bath water, use an instant read thermometer for best results). This will take approximately 1 1/2 minutes, depending on your microwave. Butter won’t totally melt.
Add water mixture to dry ingredients with the pumpkin puree. Mix on medium speed for 2 minutes, scraping the sides of the bowl a few times.
Add 1 cup more flour, beat an additional 2 minutes at high speed, scraping bowl occasionally. Mix in just enough remaining flour so the dough forms into a ball. The dough will be slightly sticky but not wet.
Turn the dough out onto a lightly floured surface. Knead until smooth and elastic, about 6-8 minutes. You know it’s done when it forms a cohesive ball and springs back when lightly pressed with 2 fingers.
Cover and let rest for 10 minutes.
Meanwhile, make the filling by stirring together the brown sugar and pumpkin pie spice.
Roll dough into a 10x15-inch rectangle using a rolling pin. Spread the melted butter all over the dough in a thin layer. Sprinkle with filling.
Beginning at the long side of the dough, roll up tightly. Slice into 12 equal pieces.
Place rolls in a 9x13-inch baking dish that’s been sprayed with nonstick cooking spray.
Cover rolls and let double in size, about 1 hour.
Preheat oven to 350°F. Once risen, bake cinnamon rolls for about 25-30 minutes or until golden brown and the center is cooked through. Cool 20 minutes before frosting.
Make the frosting: Whisk powdered sugar, pumpkin pie spice, and salt in a medium sized bowl. Add butter and cream cheese to a large bowl. Mix until smooth then mix in dry ingredients until crumbly. Add vanilla and 2 tablespoons milk, mixing until smooth and creamy (frosting will be a bit looser than regular cream cheese frosting). Add more milk as needed for consistency.
Frost slightly cooled rolls.