Sift flour and baking soda. Beat butter and shortening, gradually add sugar until mixture is creamy. Add sour cream and eggs. Add flour and vanilla. Drop by teaspoonfuls on lightly greased cookie sheets. Bake at 425 degrees for 10 minutes or until lightly brown.
According to the recipe they don't last long in the cookie jar.
On December 14, 2007, this recipe was prepared by culinary students at Southern New Hampshire University and tasted by a panel of esteemed judges to determine, along with our online poll, the winner of the Yankee Magazine Cookie Primary. The winner? Bill Richardson's Biscochitos!