Add ingredients to mixing bowl and mix with dough hook on medium speed for 8-10min. The dough will look loose at around 4-5 minutes before it comes together into a nice ball that's no longer extremely sticky.
Use a soaking wet hand and a grab and round dough in a 10 & 2 motion to tuck the dough into a taught ball. See video @__3:18__. Cover and ferment at room temperature for 30min.
After 30 minutes the dough should have gassed up quite a bit. Aggressively degas the dough so that you can perform a strength building fold and 10-2 rounding (as shown @__3:50__).
After the strength building fold and another 10-2 rounding, cover the dough again and allow to ferment at room temp for another 30min.
It will have risen a lot again after the second ferment, so aggressively degas it again. Divide into 12 equal pieces (about 100g each).
Shape and roll each piece of dough as shown @__4:38__ and place onto a baking sheet lined with oiled parchment. Don't crowd buns. I recommend using at least 2 trays. Spritz shaped buns with water and cover with a damp towel to proof for 60-90min.
The buns are well proofed when they can take a poke and slowly bounce back. Brush top and sides of buns with egg wash (1 egg + splash water).
Load into preheated 400F/205C, spritz the oven with 10-15 sprays of water, and bake for 15-18min until golden brown, rotating halfway through for even browning if needed.
Brush tops of finished buns with melted butter.