Boil the sweet potatoes, peel, and mash them.
Mix the mashed sweet potatoes with sugar and salt.
Make dough with all-purpose flour, milk, yeast, sugar, and salt.
Let the dough rest for about 10 minutes.
Divide the dough into small pieces, wrap the sweet potato filling and chocolate inside.
Bake in a preheated oven at 180°C (356°F) for 20 minutes.