Warm Whole Milk (2 cup), Canned Pumpkin Purée (1 cup), and Granulated Sugar (1/2 cup) in a medium saucepan over medium heat. Whisk until mixture is lukewarm and sugar is dissolved. Remove from heat and transfer into a mixing bowl.
Sprinkle Active Dry Yeast (1 tablespoon) on top and let sit for 5 minutes to make sure the yeast is active.
Add All-Purpose Flour (4 cup) and mix until just incorporated.
Cover with plastic wrap and set aside in a dry warm place to rise for 1 hour. The mixture should double in size.
In another bowl mix the Granulated Sugar (1 cup), Ground Cinnamon (2 tablespoon), Ground Allspice (1/2 teaspoon) together for the filling and set aside.
After the hour, add the rest of the All-Purpose Flour (2 cup), Baking Soda (1 teaspoon), and Salt (1/2 teaspoon) to the dough and mix.
Transfer onto a floured surface and knead just until a ball forms. The dough will be sticky but shouldn't be wet. Add more flour as needed. Cut in half and set one part aside.
Preheat the oven to 375 degrees F (190 degrees C).
Roll out one half of the dough into a long rectangle. Spread half the Butter (1/4 cup) throughout the dough with your fingers. Sprinkle half of the sugar/cinnamon mixture evenly on the dough making sure it reaches all edges.
Roll the dough from the longest side to the longest end. Pinch the end of the dough together so it stays.
Cut the dough into one-inch rolls and place into a dish greased with Non-Stick Baking Spray (to taste). Set aside to rise for another 15 minutes. Roll out the other half of the dough with the other half of the Butter (1/4 cup) and repeat the process.
Place raised cinnamon rolls in the oven for about 13-15 minutes. You do not want to over bake these rolls. I promise they will be done in the middle.
For the frosting, heat the Butter (1 cup) in a saucepan over medium heat until it becomes frothy and the milk fats start to brown.
Mix the browned butter in a bowl with the Powdered Confectioners Sugar (3 cup) and Vanilla Extract (2 teaspoon) until smooth. Spread on top of the warm cinnamon rolls.