Preheat the oven to 200°C (400°F).
Boil or bake the sweet potato until tender, then mash it smoothly and allow it to cool.
In a bowl, combine all-purpose flour, baking powder, and sugar.
Add cold butter and mix until the mixture resembles coarse crumbs.
Stir in the mashed sweet potato and milk to form a soft dough.
Gently roll out the dough and cut it into biscuit shapes.
Place the biscuits on a lined baking tray and bake for 12–15 minutes until lightly golden.
Allow them to cool slightly and serve warm.