Sugar Cookies with Frosting

Ingredients

• 1 cup butter (8 ounces, 16 tablespoons), softened
• 3/4 cup neutral-flavored oil (canola, vegetable, grapeseed, etc)
• 1 1/4 cups (9.25 ounces) granulated sugar
• 3/4 cup (3 ounces) powdered sugar
• 1/2 teaspoon baking soda
• 1/2 teaspoon cream of tartar
• 1/2 teaspoon salt
• 2 tablespoons sour cream
• 2 large eggs
• 1 teaspoon vanilla extract
• 5 1/2 cups (27.5 ounces) all-purpose flour
• Granulated sugar for pressing the cookies
• 3/4 cup (6 ounces, 12 tablespoons) butter, softened for frosting
• 2 tablespoons sour cream for frosting