Nutella Swirled Peanut Butter Cookies

butter, softened 3/4 cup smooth peanut butter 1/2 cup white sugar 1/2 cup packed brown sugar 1 egg 1/2 teaspoon vanilla extract 3/4 teaspoon baking soda 1/4 teaspoon salt 1 3/4 cups all-purpose flour 1/4 cup Nutella