Cut angel food cake into 3 equal layers. In small bowl, combine espresso and half cup amaretto. Spoon one third mixture evenly over each layer of cake. Whisk together quarter cup amaretto, 1 cup ricotta, half cup mascarpone and half cup powdered sugar in medium bowl. Place 1 layer of cake on plate and spread half cup mascarpone mixture on top. Add second layer and repeat. Place remaining layer on top. Whisk together remaining ricotta, mascarpone, amaretto and powdered sugar until well blended. Cover entire cake with mixture. Grate chocolate on top of cake. Refrigerate until ready to serve. Makes 24 servings. Each serving contains about 194 calories, 2 mg cholesterol, 6 grams fat, 27 grams carbohydrates, 7 grams protein. COMMENTS: Here's a wonderful, low-fat dessert for any of you who may be "waist"-watching.