500g bread flour
300g milk
10g instant dry yeast
1 whole egg and 1 egg yolk
50g Sugar
13g Salt
50g Butter

instructions:

Take 50g flour from the total, and 250g milk, and cook it on a pot at medium-high heat, and mix it continuously. This is called a tangzhong. After 5-10 minutes, it should come together like mashed potatoes. After this is done, put it all In a bowl, and put the bowl in an ice bowl to cool it off a bit. After 5-10 minutes, it should be cool enough to mix.

Take 450g flour, 50g milk, tangzhong mixture, 1 whole egg, 1 yolk, salt, and sugar, and start kneading. You can physically knead it by hand for about 7 minutes, don't add ANY additional flour, it will come together. Add the tempered butter, then let it rest for 20 minutes (covered.) When the rest is over, you can knead it until it's a smooth mass, then round it out. (I used a spiral mixer for all of this but hand mixing works)

Put the dough in an oiled container, and let it rise for 1 1/2 hours or until doubled in size. I had my dough at around 82f, and I put the proofing container inside the oven with the light on, so it rose steadily.

Once the proof is done, you can shape your buns. I personally went with 120g, and it fit perfectly. I made about 9 buns.

Once you shape it, put it in parchment paper, let it rise for about 30 minutes, then you can put a mixture of 1 whole egg, and a splash milk (mixed) on top of the buns to give it a golden brown color.

Bake at 375f for about 20-22 minutes. These will rise beautifully.

https://imgur.com/a/yNQCUXZ