In a large bowl, cream the butter, sugars and oil. Add eggs and vanilla; mix well. Add flour, salt, baking soda, cream of tartar and cinnamon. Stir in the pecans if desired. Cover and refrigerated for 3 hours or until easy to handle.
Roll into 1-in. balls. Place 2-in. apart on greased baking sheets; flatten with the bottom of a glass dipped in sugar. If desired, sprinkle with cinnamon sugar.