Combine cake mix, orange juice, water, egg yolks and orange peel. Beat 4 minutes on medium speed. Grease + line (2) pans with wax paper (9x1 1/2") Beat egg whites and cream of tartar to soft peaks. Gently spread meringue lightly over batter. Bake at 350F for 35-40 minutes. Cool completely. With flexible spatula carefully remove layer from pan, keeping meringue right-side up. Spread 1/2 whipping cream over meringue of bottom layer, then 1/2 sliced berries. Add top layer, cream + berries.