Cream together sugar and shortening. Beat in eggs. Add buttermilk; then add soda, baking powder, salt and flour and beat until mixed, then add vanilla.
Drop by teaspoon onto greased and floured cookie sheet. Bake at 350�F. until very light (about 6-8 minutes).
Frost with buttercream frosting when cool.
Frosting: Spoon the melted margarine mixture into sugar gradually, while beating with mixer. Decorate cookies with colored sugar, etc. before frosting dries.