1. Put the whole egg, milk, salt and sugar into the bread machine and mix well
2. Pour all the flour and yeast into it and knead it into a smooth dough
3. After adding the softened butter, continue to knead to the fully extended stage
4. Break the kneaded dough into small portions, add black sesame seeds, and knead well
5. Knead the kneaded dough into a dough, cover it with plastic wrap, ferment at room temperature for one hour, transfer it to the refrigerator to ferment for 16 hours, until the volume expands to 2 to 2.5 times the original size
6. After the fermentation is completed, take it out and return to temperature, divide into three equal parts after exhausting, spheronize, and ferment for 15 minutes
7. One roll: Take a loose dough, roll it up and down into an oval from the middle, turn it over, thin the bottom edge, and gently roll it up from top to bottom, roll up 1.5 to 2 circles, and relax for 10 minutes
8. Second rolling: Roll into a long strip, gently roll up from top to bottom, roll up 2.5 circles, no more than three circles
9. Close the mouth down, put it in a toast mold; place in a warm and humid place, and ferment for the second time until it is 9 minutes full
10. Put it into the oven preheated at 170°C for 40 minutes on the middle and lower layer, cover with tin foil in time after the surface is colored, buckle the side out of the oven and release the mold, let it cool and seal it for storage
