• Preheat oven to 350°F.
• Line a cookie sheet with parchment paper. .
• Beat butter, oil and both sugars until smooth.
• Add eggs, vanilla, baking soda, cream of tartar and salt.
• On low, add flour.
• Chill dough 30 mins.
• Using a large ice cream scoop, place dough on sheet.
• With the bottom of a glass, press down on each cookie.
• Bake 12 mins.
• Cool before frosting.

Frosting

• Beat butter.
• Add sugar.
• Add vanilla, milk, sour cream and coloring.
• Beat until fluffy.
• If too thin, add more sugar. If too thick add more milk.
• Frost each cookie!