Combine sugar, sour cream, eggs, butter, and shortening. Beat at medium speed until light and fluffy.
Add flour, baking powder, baking soda, vanilla, and salt. Mix well until soft dough forms cover and chill 1-2 hours.
Heat oven to 350
roll out dough to 1/4 inch thick press out cookies and place on ungreased cookie sheet bake 6-8 minutes or until just lightly golden brown. Cool on rack when completely cool frostin the cookies.