Warm the milk to about 40°C / 105°F — it should feel barely warm on your wrist, never hot.
Whisk the yeast and the 25 g sugar into the warm milk and leave it 5 minutes until the surface looks foamy.
Combine the all-purpose flour, glutinous rice flour and salt in a large bowl.
Pour in the yeast milk and the 1 tbsp oil, then stir with a spatula until no dry flour remains.
Knead in the bowl for 4 to 5 minutes — the dough stays soft and slightly tacky, so oil your hand rather than adding flour.
Cover the bowl and let it rise at 25 to 28°C / 77 to 82°F for 60 to 90 minutes, until roughly doubled.
Mix the brown sugar, cinnamon, chopped peanuts and 1 tbsp flour in a small bowl and set it beside the stove.
Punch the risen dough down gently, then let it rest uncovered for 10 minutes.
Oil your hands and divide the dough into 8 equal pieces, about 60 g each.
Flatten one piece into a disc in your palm, spoon in 1 heaping tablespoon of filling, and pinch the edges shut into a sealed ball.
Heat 2 tbsp oil in a heavy skillet over medium heat until a scrap of dough sizzles on contact.
Place two balls seam-side down and fry undisturbed for about 30 seconds so the base sets.
Flip them, then press each one slowly with an oiled flat press or the back of an oiled spatula to a disc about 10 cm / 4 inches wide and 1 cm / 3/8 inch thick.
Fry 90 seconds to 2 minutes per side, until the edges turn deep golden and the surface blisters.
Lift onto a rack or paper towel and let them sit at least 3 minutes before eating — the filling inside is far hotter than the dough.
Wipe the pan, add fresh oil, and repeat with the remaining dough.