In a large bowl, whisk together the warm milk, yeast, and ½ tsp sugar and let it rest until fluffy for 5-7 minutes
In a large bowl (preferably of a stand mixer), add the flour, the remaining sugar, salt, eggs, butter, vanilla, and the activated yeast
Mix them well until combined for about 3-4 minutes, then cover with a cloth or plastic wrap and let it rest at room temperature for 4-5 minutes
Knead the dough with a stand mixer or using your hands for 8-10 minutes
Transfer the dough into a large bowl and cover it with plastic wrap and let it sit for 40-45 minutes until doubled in size
Place the dough in the refrigerator and let it rest for 1 ½ hours
In a medium bowl, mix the butter, sugar, cinnamon, salt, and vanilla
Place the dough onto a lightly floured surface and roll the dough into a rectangle (around ¼ inch thick)
Evenly spread the cinnamon mixture over the dough (optionally add caramelized pumpkin puree)
Starting from the long end, roll the dough down to the bottom edge
Using a string or sharp knife cut the dough into 8-9 equal rolls
Place the buns on baking sheets or a cast iron skillet lined with parchment paper and cover with a clean kitchen towel
Let it rest for 40-45 minutes at room temperature
Preheat the oven to 350°F and bake the buns for about 25-30 minutes
Remove them from the oven and let them cool for 20 minutes
