LEMON MERINGUE LAYERED CAKE

Steps:

• Heat oven to 350ºF.
• Prepare cake batter and bake as directed on package for 2 (9-inch) round layers, blending half the lemon zest into batter before pouring into prepared pans. Cool cakes in pans 10 min. Invert onto wire racks; gently remove pans. Cool cakes completely.
• Meanwhile, mix cornstarch and 2 Tbsp. sugar in medium saucepan. Gradually stir in water. Bring to boil on medium heat; cook 8 min., stirring constantly. Remove from heat. Add dry gelatin mix; stir 2 min. until completely dissolved. Stir in lemon juice and remaining zest. Refrigerate 40 min. or until slightly thickened, stirring occasionally.
• Heat oven to 450ºF. Place 1 cake layer on parchment paper-covered baking sheet. Beat egg whites and cream of tartar in small bowl with mixer on high speed until foamy. Gradually beat in remaining sugar until stiff peaks form; spread onto top of cake layer on prepared baking sheet. Bake 5 to 7 min. or until meringue is golden brown.
• Place remaining cake layer on serving plate; spread with gelatin mixture, then COOL WHIP. Top with meringue-topped cake layer.