1 c. butter, softened
1 c. sugar
1 c. sifted powdered sugar
1 c. vegetable oil
2 eggs
1 tsp. vanilla extract
4 1/2 c. all-purpose flour
1 tsp. baking soda
1 tsp. salt
1 tsp. cream of tartar

Cream butter, while gradually adding 1 cup sugar and powdered sugar, beat well with electric mixer on medium speed. Add oil, eggs and vanilla.

Combine flour and next 3 ingredients. Add to creamed mixture and mix well. Cover and chill overnight. Shape dough into 1 inch balls. Place 3 inches apart on ungreased cookie sheet.

Dip a flat bottomed glass in sugar. Flatten cookies to 1/4 inch thickness. Bake at 375 degrees for 5 to 8 minutes until cookies are set but not too brown. Cool on rack. Yield 6 1/2 dozen.