Beat butter, cream cheese, sugar, salt and vanilla until fluffy. Add egg and milk; mix well. Gradually add flour, stir in walnuts. Drop by teaspoonful onto a lightly greased cookie sheet about 2 inches apart. Bake 325, 20 minutes. Remove to wire rack to cool.
This cookie doesn't need icing or powdered sugar but if you wish you can dip one end in chocolate or do a drizzle icing. My family loves them just the way they are. They also freeze well.