1 . Stage
Beat soft butter with powdered sugar, vanilla, salt.
2 . Stage
Add protein and beat well again.
3 . Stage
Stir in the flour, transfer the finished dough into an envelope and place cookies on a baking sheet covered with baking paper.
4 . Stage
Give any shape, I have, in honor of the holiday, hearts.
5 . Stage
Bake at 180 degrees for 20 minutes, cookies should not be dark in color.