1 c. butter
1 c. oil
1 c. white sugar
1 c. powdered sugar
2 eggs
4 1/2 c. flour, sifted
1 tsp. baking soda
1 tsp. cream of tartar
1/4 tsp. salt
1 tsp. vanilla

Mix butter, oil, sugars and eggs. Then add remaining ingredients. Chill. Roll into balls; place on ungreased cookie sheet and press with glass dipped in sugar.

Bake at 350°F for 10 to 12 minutes. These cookies really melt in your mouth.