Peel the sweet potatoes, boil them, and mash them.
Mix eggs and sugar together.
Combine the mashed sweet potatoes with the mixed eggs and sugar.
Add milk and melted butter, then mix well.
Sift in the flour and mix evenly.
Pour the batter into a cake pan.
Bake in a preheated oven at 180°C for 30 to 35 minutes.