Frosted Walnut Buttermilk Cookies

1/2 cup butter, softened
1 cup sugar
1 egg
1 teaspoon vanilla extract
2-1/2 cups all-purpose flour
1/2 teaspoon baking soda
1/2 teaspoon salt
1/2 cup buttermilk

Frosting:
3 tablespoons butter, softened
3-1/2 cups confectioners' sugar
1/4 cup milk
1 teaspoon vanilla extract
1/2 cup finely chopped walnuts, optional

In a mixing bowl, cream butter and sugar until light and fluffy. Beat in egg and vanilla. Combine flour, baking soda and salt; add to the creamed mixture alternately with buttermilk and mix well.

Drop by rounded tablespoonfuls 2 in. apart onto greased baking sheets. Bake at 375° for 10-12 minutes or until edges are lightly browned. Remove to wire racks to cool.

For the frosting, combine butter, confectioners' sugar, milk and vanilla in a mixing bowl; beat until smooth. Frost the cookies; sprinkle with chopped walnuts if desired. Makes 3 dozen.