For the Cinnamon Rolls: 

1. Heat the milk in a small, microwave-safe bowl or measuring cup for 45 seconds or until the milk is between 115°F and 120°F. Stir in the sugar until it dissolves.
2. Whisk the melted butter, pumpkin puree, and egg in a stand mixer bowl until just combined. Add the flour, pumpkin pie spice, baking powder, baking soda, salt, and yeast, and stir until the dough is dry and crumbly.
3. Attach the bowl to the stand mixer along with a dough hook. Mix at low speed (1) and pour a slow stream of the milk mixture into the dough. Once all of the milk has been added, scrape down the sides of the bowl, then increase the speed to medium (5). Let the dough mix for 5 minutes or until it has formed into a large ball, and the majority of it has pulled away from the sides of the bowl. It should spring back slowly when poked and be a tiny bit tacky.
4. Turn the dough out onto a well-floured surface, and knead for another five minutes or until it can stretch without tearing too quickly. Add more flour to the surface if it starts to stick.
5. Press the dough into a large rectangle with your hands, then use a floured rolling pin to roll the dough into a 12×18 rectangle that’s about ¼ inch thick.

Pumpkin Spice Filling: 

1. In a small bowl, stir together the butter, brown sugar, and pumpkin pie spice until a thick paste forms.
2. Spoon the filling over the flattened dough, and spread it out evenly with the back of a spoon or offset spatula. Leave about ½ an inch of one of the long sides of the dough without the filling so you can seal the cinnamon roll closed when you roll it.
3. Use a pizza cutter or a large, straight-edge knife to slice the dough along the long edge into 12 equal strips about 1.5 inches wide. Tightly roll each strip and press the end into the roll to close it off. Alternatively, you can tightly roll up the long edge into one big log, then use a sharp knife or floss to cut the log into 12 equal rolls.
4. Place the rolls into a greased 9×13 baking pan or dish, cover the pan with plastic wrap, and store somewhere warm for 60-80 minutes or until the rolls have doubled in size.
5. Preheat the oven to 375°F. Remove the plastic wrap from the rolls, and bake for 20-22 minutes, or until the rolls are lightly browned on top and have filled the pan completely. Let the rolls rest for 10 minutes.

Cream Cheese Frosting:

1. Beat the softened cream cheese until it’s free of lumps. Add the melted butter, milk, and vanilla extract, and mix until combined. Next, add the powdered sugar and beat until smooth. For a thicker frosting, add more powdered sugar, 1 tablespoon at a time, until the desired consistency is reached. For a thinner frosting, add more milk, 1 tablespoon at a time.
2. Spread the frosting over the warm cinnamon rolls and serve. Let the cinnamon rolls cool to room temperature before storing them in the refrigerator in an airtight container.