Add the flour, sugar, salt, yeast, and milk powder to a large mixing bowl/stand mixer bowl. Mix until combined.
Add in the milk, butter, and tangzhong.
Knead the dough until a ball forms
Separate the dough in half and add matcha powder to half
Cover the dough and let rest until doubled in size (40-60 minutes)
Knead out both pieces of dough on a floured surface. Use a rolling pin and roll out the dough to the same size
Place the pieces of dough on top of each other. Use rolling pin to roll it out
Roll up the dough into a log
Cut the dough into 6 equal sized pieces
Place the dough with the swirl side facing up in a bread loaf pan
Let rest 30 minutes
Brush with egg wash. (this step is only if you use a regular bread loaf pan. It's not necessary if you use a pullman loaf pan like I did)
Bake at 170C/338F for 30 minutes
Let bread cool before slicing.