BLACK BOTTOM PIE --GRAHAM CRACKER CRUST:-- 1 1/4 c. graham cracker crumbs 1/2 c. diet margarine --FILLING-- 1 envelope unflavored gelatin 3/4 c. part-skim ricotta cheese 12 packets sweetener 1 packet low-calorie whipped topping mix 1 1/2 c. skim milk 1 tbsp. vanilla extract 1/4 c. cocoa Combine crumbs with diet margarine by cutting in softened margarine until mixture resembles coarse crumbs. Press firmly in bottom and sides of 8 or 9 inch pie pan. Bake in preheated 350 degree oven for 8 to 10 minutes. Cool. In small saucepan, sprinkle gelatin over 1/2 cup skim milk. Let stand one minute. Heat, stirring constantly until gelatin dissolves. In blender or food processor, blend ricotta until smooth and add gelatin mixture, remaining 1 cup milk and vanilla. Continue blending until completely smooth. Remove half the mixture, set aside. To mixture still in blender, add 6 packs sugar substitute and cocoa. Blend thoroughly. Pour blender mixture into crust, chill for 30 minutes or until partially set. At the same time, chill remaining mixture for 30 minutes. Prepare whipped topping mix according to package directions gradually adding remaining 6 packets sugar substitute. Whisk into reserved, chilled mixture until blended smoothly. Spoon over chocolate layer; chill until set. Garnish with dusting of cocoa. Makes one (8 or 9 inch) pie or 8 servings.