1. After the butter has softened, add in caster sugar, add vanilla extract, and mix well
2. Then add the whole egg liquid and mix well
3. Add salt, low powder, black tea crumbs
4. Stir evenly with a spatula
5. After wrapping it into a cylindrical shape with plastic wrap, put it in the refrigerator for about half an hour
6. Preheat the oven at 180 degrees, take out the frozen dough, use a knife to cut into thin slices about 0.5 cm thick
7. Put into the preheated baking tray, 180 degrees, middle layer, upper and lower tubes, 30 minutes
8. After baking, take it out and let it cool and keep it sealed
Tips:Pay attention to the coloring of the biscuits later, don’t bake them
