1. Cut butter into small pieces and soften at room temperature, add powdered sugar
2. Use an electric whisk to mix well, add egg yolk and continue to mix well
3. Sift into the powder
4. Use a rubber spatula to cut and mix into dough
5. Knead into a strip with a diameter of 2.5cm, wrap it with plastic wrap and freeze in the refrigerator for 2 hours
6. Brush with a thin layer of egg white
7. Roll with a layer of coarse sugar
8. Roll with chopped almonds
9. Cut into 2.5cm high cylinders and place them evenly on the baking tray
10. Put it into the preheated oven and bake at 170 degrees for 20 minutes
11. Take it out to cool, melt the white chocolate in warm water, and put it in a piping bag
12. Use the smallest round flower mouth to squeeze out the annual rings on the surface of the biscuit
