2 cups butter -- softened
1 1/2 cups sugar
4 egg yolks
2 teaspoons vanilla
4 1/2 cups unbleached flour
1/2 teaspoon salt
Preheat oven to 350 degrees. With an electric mixer cream together butter and sugar. Add egg yolks and vanilla and mix well. Sift flour and salt together and beat into butter mixture until well mixed.
Roll dough into a ball and refrigerate, covered, for about an hour.
When ready to bake, use an ungreased cookie sheet and place cookies 1 inch apart. Bake for about 10 minutes, but do not brown them. Remove cookies from cookie sheet after cooled. Decorate, if you like. Makes 6 to 8 dozen.
For the frosting we just mix confectioners sugar with milk until we get the consistency we want. It takes a whole lot of sugar and just a bit of milk (you can use water instead if you want).
recipe also posted here.