1. Butter softened at room temperature
2. Add powdered sugar
3. Stir evenly with an electric whisk
4. Add plain yogurt, then slice a whole lemon zest into zest and add it to the basin
5. Beat again evenly
6. Mix low-gluten flour, milk powder and baking powder into a basin
7. Use a rubber spatula to mix into a uniform batter
8. Put it in a piping bag, with a medium six-tooth mouthpiece
9. Baking pan liner, extruded "S" type biscuit blank
10. Preheat the oven, turn on the heat to 170 degrees, and bake at 160 degrees for about 20 minutes. Do not open the oven door after turning off the fire. Continue to simmer for about 10 minutes at the remaining temperature.
