In a mixing bowl add the warm milk, sugar and yeast. Stir and let it get foamy, around 10 minutes.
In your stand mixer bowl add the 2 and 1/2 cups of bread flour, salt, milk powder and stir. Add the tangzhong mixture, heavy cream, egg.
Pour in the foamy yeast mixture and mix this in the stand mixer fitted with a dough hook attachment. Mix for 5 minutes until sticky but no dry pockets of flour.
Add the remaining 1/4 cup of flour, a little at a time mixing until the dough is soft. (You may not need to use it at all)
Add the butter one table at a time and mix again until incorporated before adding the next tablespoon.
Once it dough is smooth form into a ball and line the mixing bowl with a little oil, place the dough in it cover with cling wrap and let it rise for 2 hours or until doubled.
After it has doubled in size, punch down and transfer it to a lean kitchen surface. Divide the dough into 4 equal parts. Roll each part into a small log and place in a 9 inch loaf tin. Cover and let it rise for 1 hour until doubled.