1 (9" or 10") round angel food cake
1 (21 oz.) can lemon cream pie filling
1 (8 oz.) carton lemon yogurt
1 (8 oz.) container frozen whipped topping, thawed
Lemon slices (opt.)

Cut cake horizontally into 4 layers using a serrated knife. In medium bowl, combine pie filling and yogurt. Blend well. Spread 1/3 of filling (about 1 cup) between each cake layer. Frost top and sides with whipped topping. Garnish with lemon slices.