Double Vanilla Delights~Rainbow Cookies Author: munchkinmunchies Serves: 20 sandwich cookies Ingredients Cookie Ingredients • 1 Tablespoon pure vanilla extract • 1 cup butter, softened • ½ cup sugar • ½ cup powdered sugar • 1 egg • 2 cups all-purpose flour • ½ teaspoon baking soda • ½ teaspoon cream of tartar • ¼ teaspoon