Triple Chocolate Chip Cookies

Ingredients (13)

• 2 1/4 cups flour
• 1 teaspoon cornstarch
• 1 teaspoon baking soda
• 1 teaspoon salt
• 1 cup cold unsalted butter, cut into cubes
• 1 cup brown sugar
• 1/2 cup white sugar
• 1 egg
• 1 egg yolk
• 2 teaspoons vanilla extract
• 3/4 cup white chocolate chips
• 3/4 cup milk chocolate chips
• 3/4 cup semi sweet chocolate chips