1 c. butter, softened
1 c. vegetable oil
1 c. sugar (white)
1 c. sifted powdered sugar
2 eggs
4 c. flour
1 tsp. baking soda
1 tsp. cream of tartar
1 tsp. salt
1 tsp. vanilla
1 (12 oz.) semi sweet chocolate chips

Combine first 5 ingredients in a large mixing bowl. Beat until smooth. Combine flour, soda, cream of tartar and salt. Add to butter mixture. Beat until smooth. Stir in vanilla and chocolate chips. Shape into 1" balls and roll into sugar. Place 2" apart on ungreased pan. Bake at 350 degrees for 10 to 12 minutes.