Line an 8 1/2- x 4 1/2- x 3-inch loafpan with plastic wrap, smoothing plastic wrap in corners and on sides of pan. Arrange one-third of ladyfinger halves, cut sides facing in, on bottom and around sides of loafpan; set aside.
Fold whipped topping into yogurt. Spoon half of yogurt mixture into prepared loafpan. Spoon 1/4 cup caramel syrup over yogurt mixture. Swirl caramel syrup with a knife to create a marbled effect. Arrange half of remaining ladyfinger halves on top of caramel. Repeat layers with remaining yogurt mixture, remaining 1/4 cup caramel syrup, and remaining ladyfinger halves. Cover and freeze at least 8 hours.
To serve, invert dessert onto a serving plate, carefully peeling away plastic wrap. Cut into 10 slices, and top evenly with raspberries.
Use the microwave to thaw frozen reduced-calorie whipped topping and raspberries and to soften nonfat or low-fat frozen yogurt in seconds. Follow these times:
-To thaw a 4-ounce container of frozen reduced-calorie whipped topping, microwave it, uncovered, at MEDIUM-LOW (30%) for 1 to 2 minutes or until topping is thawed.
-To thaw frozen berries, place the berries in a medium bowl and microwave them, uncovered, at MEDIUM (50%) for 5 to 6 minutes or until the berries are thawed.
-To soften frozen yogurt, microwave the container of yogurt, uncovered, at MEDIUM-LOW (30%) for 20 seconds at a time until the yogurt is softened.
Cooking Light Low-Fat, Low-Calorie Quick and Easy Cookbook