Mix the first three ingredients thoroughly. Sift together flour, cream of tartar, baking soda and salt. Stir the two mixtures together. Roll into balls the size of walnuts. Dip into a mixture of equal parts sugar and cinnamon. Place two inches apart on a lightly greased baking sheet. Bake until lightly browned but still soft. (8 to 10 minutes) at 350 degrees F.
Makes 3 dozen cookies.