Mix all the dry ingredients (flours, sugar, salt, milk powder, and yeast) together in a a mixer bowl. Add the egg and cold water. Using an electric mixer fitted with a dough hook attachment, knead to form a dough.

Add butter, and knead until dough becomes soft and elastic. Set dough aside to ferment for 60 minutes.

Divide the dough into 2 equal portions. Shape each portion into a ball. Set aside for another 10 minutes to rest.

Using your fingers, flatten each into a rectangle, making the short side about the same length as the bread tin. Roll up each like a log or Swiss roll.

Grease two (2) bread or loaf tins (length 20 cm x width 11 cm x height 11 cm). Put one rolled dough in each tin. Set aside to proof for 45 minutes, or until dough has doubled in size.

Using a sharp knife, score a line once lengthwise and slightly off centre, across the top of each loaf. Drop the butter, and sprinkle the sugar, equally between the 2 loaves, into the slits and on the tops.

Bake at 180 deg C for 30 minutes. Remove the loaves from the tins immediately, and set aside to cool completely on a cooling rack. Slice and serve as desired.