Family Tested & Approved
brown sugar, firmly packed
In large bowl, cream together butter, sugars and oil. Stir in eggs and vanilla.
In separate bowl, combine flour, baking soda, salt and cream of tartar. Slowly add to creamed mixture. Beat until well blended.
Roll dough into balls approx the size of walnuts and roll balls into additional sugar. Place balls onto ungreased cookie sheets. Press each ball down with the bottom of a glass or a cookie stamp.
Bake at 350 for 8-10 minutes.