sprinkle gelatin over 1/2 cup water: let stand 5 minutes to soften. beat egg yolks slightly in top of a double boiler. stir in 1 cup splenda and milk; cook over hot water, stirring constantly, until thick, stir in gelatin, remove from heat. Combine lemon rind and cottage cheese, stir into gelatin mixture. refrigerate until mixture forms peeks when pulled with a fork. beat eggs white untill frothy. add 1/4 cup slenda, beating eggs untill stiff peaks form. slowly fold egg mixture into cottage cheese mixture. fold in whipped topping, turn into 9 inch springform pan. chill until firm. release spring and garnish with wipped topping if desired.