1. Boil the coffee with boiling water, let it cool, and add yeast powder.
2. Add a teaspoon of cooking oil, flour, and knead into a softer dough (oily skin).
3. Cornmeal and flour are mixed at a ratio of 2:1, and edible oil is added to synthesize pastry.
4. Knead the oily skin, pull it into a small dose, and press it flat.
5. Roll it out and put a small piece of shortbread on it.
6. Wrap it up like a bun, and then put it mouth down.
7. Roll it out, roll it up and roll it out, roll it up and roll it out again (the more times, the more layers).
8. Finally, roll it out, wrap it with red bean paste, and place it on a baking tray (spread a layer of tin foil so that it will not stick, or brush it with a layer of oil).
9. Put it in the oven, bake at 150 degrees for 25 minutes, take it out, brush with egg yolk liquid, sprinkle with black sesame seeds, and bake for another 5 minutes.
