If making your own sweet potato puree, add ¾ cup of roasted sweet potato (skin removed) and ¼ cup of warm milk to a blender or food processor. Blend until smooth and pureed.
Add ¾ cup of warm milk to a large mixing bowl. Sprinkle with active dry yeast.
Cover with a dish towel or plastic wrap and let proof for 10 minutes.
When the yeast is foamy, stir in the sweet potato puree, ¼ cup melted butter, brown sugar, cinnamon and salt.
Using a wooden spoon or stand mixer, add flour ½ cup at a time. Mix in flour until the dough is just holding together. If kneading by hand, sprinkle a clean surface with flour. Knead the dough until smooth and elastic, about 8-10 minutes. If using a stand mixer, set to low and knead until the dough is smooth and elastic, about 2-3 minutes.
Lightly oil a large mixing bowl with cooking oil. Add the dough, flipping to coat with oil. Cover tightly with plastic wrap or a towel and set in a warm place. Let rise until doubled in size, about an hour.
Once doubled in size, use your fist to deflate the dough. Knead lightly a few times to fully deflate. To make the rolls, divide the dough into four equally sized pieces. Divide each of these pieces into three so that you have a total of 12 equally sized pieces of dough. To form into a ball, cup each piece lightly in your palms and roll.
Lightly oil a 10x10 or 9x13 baking dish. Evenly space the 12 rolls in the dish. Cover and let rise in a warm place until double in size, about 20-30 minutes.
Meanwhile, preheat the oven to 350 degrees F.
Once doubled in size, brush the rolls with 2 tablespoons melted butter. Bake at 350 degrees for 15-18 minutes, or until the tops are lightly golden.
Notes
Warm milk in the microwave until 108-110 degrees F. Use a food thermometer to check the temperature.
Use a total of 1 cup of milk in this recipe. If you don't make your own sweet potato puree you will stir 1 cup of milk with the yeast instead of ¾ cup milk.
1 packet active dry yeast = 2 and ¼ teaspoons yeast.
I recommend using a kitchen thermometer to temp your milk and butter after heating. You want the milk to be between 108-110 degrees; any warmer may kill the yeast and cooler may prevent the yeast from activating. Temp the butter to make sure that it isn't over 110 degrees (this may scald the yeast).
Yeast dough rises best in a warm environment. If your kitchen is cold (less than 75 degrees), set your oven to the lowest temp (180-200 degrees). Once heated, turn the oven off and place the dough in the closed (and off) oven to rise.