Peel the sweet potatoes and boil them as whole in water for 10-15 minutes. Pierce the biggest piece is a fork and it should go in with NO resistance.
Transfer the potatoes on to a plate and mash with a fork until smooth. Let it cool to room temp.
Transfer cooled mashed potato to a mixing bowl, add sugar and salt then stir until combined. Add tapioca starch and flour, then sift in baking powder, then stir everything together briefly just to see where the dough is at in terms of moistness.
Add coconut milk, 1 Tbsp at a time, until all the flour can be incorporated. Make sure you stir in that 1 Tbsp of coconut milk well before adding the next.
Once all the dry flour has been incorporated, you should be able to form the dough into balls easily.
Scoop up a heaped teaspoon worth of dough and roll them into balls.
Add enough oil into your pot and heat the oil to 170°C, add the balls and make sure you stir them to avoid a burnt brown patch where they touch the bottom of the pot.
Keep frying them till it started to float and till colour has turned golden with a nice a crisp crust.
Scoop them up, shake off excess oil, then place them on a paper-towel lined plate.
Dust some icing sugar and serve.