40grbutter3 Tbsp, cold, unsalted. I used chilled coconut oil
Activate the yeast:
Place the yeast, warm water (make sure it's comfortably warm so it doesn't kill the yeast),and sugar in a bowl. Let it sits for 10 minutes. It will turn foamy
Make the dough:
Edited: the butter/coconut oil should be chilled and not softened. Cut into small pieces before adding to the dough
Place all the ingredients for the dough in a mixing bowl of a stand mixer. Use a dough hook attachment and knead the dough until you get a rough dough. Add chilled butter pieces or coconut oil in a bit at a time
The dough will turn into a sticky mess. Do not add any flour. Keep kneading at a low speed until the butter/coconut oil gets absorbs by the dough, it may take 5 minutes or so. The dough should be soft, stretchy, shiny and just slightly sticky to touch
Cover and let the dough proof at a warm place. I use the oven's bread proof function and let it rises until double in size.
Shape the dough:
Once the dough is proofed, punch the air out and knead a few times. Divide the dough into 8 smaller dough. Work with one dough at a time while keeping the rest covered. Flatten and fold towards the center to form a round dough ball. Place seam side down in the air fryer basket lined with a parchment paper at the bottom (update: don't line the side with parchment as the buns won't cook evenly). You can also use a non-stick spray to spray the basket on the side. Some people have trouble with buns not cooked through at the bottom when lined with parchment paper, you can try to poke few small holes on the parchment paper.
If you don't want to use the air fryer basket, you can remove the basket and use a round baking pan that can fit in your air fryer. Place the shaped dough in this pan. Continue with the rest
Let the dough proof again at a warm place until puffy and doubles in size again, about 40 minutes to one hour
Air-baked the dough:
Preheat the air-fryer at 320 F (160 C) for 5 minutes. Place the air-fryer basket inside the air fryer and bake for 18-20 minutes. I baked mine for 20 minutes. The baking temperature and time are just for references. You may have to experiment with your air fryer
You can bake this in the oven too. Bake in a preheated oven at 350 F (180 C) for 15 minutes.
Brush with some butter or coconut oil on top while the buns are still warm. Remove the buns from the air fryer and let them cool down completely on a cooling rack
Air Fryer Ultra-Soft Eggless Pull-Apart Milk Buns/Rolls https://whattocooktoday.com/air-fryer-milk-buns.html