Mash the steamed sweet potatoes, then mix with glutinous rice flour, oil, sweetener, milk, and black sesame seeds.
Shape the dough into balls and cook in an air fryer at 190°C (374°F) for 5 minutes, flip, then cook at 180°C (356°F) for about 10 more minutes.
Place on a cooling rack to cool and it's ready to serve.