Preheat oven to 375 degrees. Grease cookie sheets.
In a large bowl, with a mixer, cream butter with sugar until light and fluffy. Beat in egg and vanilla. Add flour and salt and blend thoroughly.
On a lightly floured surface, roll out dough to 1/8 inch thickness and cut with your favorite floured cookie cutter. Bake in preheated oven for 8 minutes or until edges are lightly browned. Transfer cookies to rack to cool.
In a bowl, with a mixer, combine cream cheese, sugar and milk until creamy. Frost cooled cookies. Makes 5 to 6 dozen cookies. Enjoy!