1 stick butter
1 c. sugar
1/2 c. oil
1 egg
1 tsp. vanilla
2 1/2 c. flour
1 tsp. baking soda
1 tsp. cream of tartar
1/2 tsp. salt

Beat butter, sugar, and oil together until fluffy. Add rest of ingredients. Shape into balls about the size of a walnut. Dip in sugar; flatten with glass. Bake at 350 degrees for 10 minutes.