Step 1

Stovetop: Combine ingredients in a small pot and place over medium heat

Step 2

Stir and continue to heat until the mixture turns into a pudding-like consistency.

Step 3

If you have a digital food thermometer, the mixture should reach ~149 F

Step 4

Microwave method (preferred for its ease): Add ingredients to a microwave proof jar (I like to use glass canning jars like Ball).

Step 5

Stir ingredients very well and then microwave for 25 seconds; remove and stir well again.

Step 6

Return to microwave and cook for 15 seconds, then remove and stir very well. Repeat this process until the mixture has thickened up when stirred (typically requires a total of three 15-second cycles).

Step 7

Cover and cool until it is room temperature or at least 120 F (can be stored for up to 2 days in the refrigerator; remove and bring to room temperature before using)

Step 8

Combine all dry ingredients in a bowl of a standing mixer

Step 9

Add tangzhong (cooled), egg, milk, and butter.

Step 10

Mix on low speed until all the ingredients are well incorporated.

Step 11

Increase speed to medium and knead for 8 to 10 minutes.

Step 12

Allow dough to rest for 5 minutes before testing for windowpane.

Step 13

Knead until the windowpane develops (windowpane is when you break off a walnut sized piece of dough and stretch it gently until super thin; "almost see through").

Step 14

After kneading and achieving the windowpane, divide dough into 5 equal pieces and form into balls.

Step 15

Cover balls and let rest for 15 minutes (using a damp lint free towel or plastic wrap sprayed with cooking spray so it does not stick to the dough).

Step 16

After the dough has rested, flour each ball on both sides and then, using a rolling pin, flatten each ball into an rectangular shape that is about 1/4 thick.

Step 17

Fold the edges of the dough over so they meet in the middle.

Step 18

Roll up the dough into a cylindrical shape.

Step 19

Place each log in loaf pan (make sure seam is on bottom of pan and the rolled parts are facing front and back of pan). Note that the USA pullman pan that I use does NOT require greasing; please grease your pan if not using USA pan

Step 20

Cover pan with lid (if you have one) OR lightly oiled plastic wrap, and proof from 45 to 70 minutes (total time will depend on temperature of dough and of kitchen)

Step 21

The bread dough is ready to bake when it rises to just within an inch of the top of the pan. Note that when it gets close to this, begin to preheat your oven (365 F).

Step 22

Just before baking, brush the top of the bread with egg wash.

Step 23

About 15 minutes before bread has finished proofing begin to preheat the oven.

Step 24

Preheat oven to 365 F and position rack in bottom third of oven for baking the bread.

Step 25

When bread has risen within 1 inch of top of pan, brush the top with egg wash,, place bread in oven and bake the bread for 45 minutes.

Step 26

Check bread after 20 to 30 minutes of baking for browning and place aluminum foil loosely over top of bread if it has picked up too much color or is browning too quickly.

Step 27

After 45 minutes of baking, remove bread and gently tilt loaf pan to remove bread. Let bread cool completely before slicing or storing.

Step 28

Slice into 1/2 inch slices or to taste.

Step 29

After it has completely cooled, store wrapped for up to 4 days or freeze for up to 3 months.