These luscious squares have a raspberry jam layer tucked between a crisp sugar-cookie crust and a lemon topping. Be sure to provide forks, paper plates and plenty of napkins for serving these old-fashioned favorites.
Recipe courtesy of Williams-Sonoma and adapted from Williams-Sonoma Outdoors Series, Picnics and Tailgates, by Diane Rossen Worthington (Time-Life Books, 1998).