Not OP, but here’s a recipe that I follow whenever I wanted to make these at home: https://thewoksoflife.com/chinese-bbq-pork-buns-cha-siu-bao/
That’s the exact recipe I used :) except I forgot to turn the oven down in the last step lol.
I think it still worked out well in the end! They have a nice brown color have a crumbling flakiness. Each time I followed the recipe, my buns turned out paler than I wanted. Then again, I also had to substitute the different flour types with only all-purpose flour since I didn’t want to buy different flour types.