The BEST Sugar Cookies

My mother-in-law and I made the most amazing sugar cookies I've ever had so I thought I would share the recipe with you guys!

1 C. of butter
1 C. of oil
1 C. of sugar
1 C. of powdered sugar
2 eggs
1 tsp. of vanilla
4 C. of flour
1 tsp. of each: salt, baking soda and cream of tartar

Cream together butter, oil and sugars. Add other ingredients and mix well. Chill at least 1 hr. Drop by tsp. on greased cookie sheet. Flatten with fork. (I didn't flatten them) Bake @ 350 for 10-12 minutes. Sprinkle with sugar (I didn't sprinkle with sugar either). They melt in your mouth! Enjoy!