1. Separate the yolks of the cooked eggs, then crush them, sieve them into a bowl and set aside
2. Prepare a large bowl, add the softened butter, salt, and powdered sugar, and beat with a whisk until fluffy
3. Add the sifted egg yolk, continue to beat with a whisk, and mix well
4. Sift in cornstarch and low-gluten flour, stir evenly, then knead into a dough
5. Cover with plastic wrap and put in the refrigerator for 30 minutes
6. After the dough is refrigerated, take it out, pull a small ball of dough, and knead it into a ball
7. Put the ball in the oven tray, press it with your thumb, then put it in the preheated oven, bake at 190 degrees for 15 minutes
