Wash the sweet potatoes thoroughly, boil them, peel off the skin, and mash them.
Add sugar and salt to the mashed sweet potatoes and mix well.
Add eggs, milk, and melted butter, then blend till fully combined.
Sift flour and baking powder into the mixture and finish making the batter.
Fill muffin cups with the batter.
Bake in a preheated oven at 180°C for 20 minutes.