This little thing is easy to do and it is delicious!
Add butter to sugar
Egg yolk solution is added in three times and blended with butter.
Sift into flour and salt and add 2 to knead a dough
Knead the dough into cotton (so thick as two silver coins) and cover it with a bone cookie
Enter the oven 180 degrees for 10 minutes (see the situation plus or minus time)