Put fresh milk in a saucepan and warm on low heat, transfer to the mixing bowl, sprinkle instant yeast and let stand for 5-10minutes.
OR if using evaporated milk, mix 6 tablespoons evaporated milk with enough boiling water (about 2 Tbsps) to make ½ cup of milk in a large mixing bowl. Add yeast and let stand 5-10 minutes
When yeast mixture is frothy, add salt, 3 tbsp sugar, mashed sweet potato, melted butter and beaten eggs.
Mix well with a whisk or wooden spoon.
Add 3 cups of flour to the mixture and using wooden spoon, stir until shaggy dough forms.
Reserve the ½ cup for dusting the surface and your hands and if the dough is too sticky.
Turn out dough into a lightly floured surface and knead for about 3 minutes.
Form dough into a bowl.
OIl the mixing bowl and put the ball of dough in it, cover with plastic wrap and let it rise for an hour or until double in size.
After an hour, remove plastic wrap and punch dough down to release the air.
Transfer to your work surface and roll dough into a rectangle (13x20) to make 8 big cinnamon rolls or divide dough into 2 and make 2 batch of smaller rolls (16 pcs)
In a small bowl, combine brown sugar, cinnamon powder and nutmeg, mix well.
Brush dough with melted butter and sprinkle cinnamon sugar mixture on top.
Add raisins, if using.
Roll dough beginning from the end nearest you.
Lighty pinch end to seal.
Cut rolled up dough into 8 equal pieces and arrange on a lighly greased baking dish.
Allow to rise until it's doubled, about 30 mins.
Preheat oven to 375 F degrees.
When dough is ready, bake in the preheated oven for about 20 mins or until brown on top.