Prehat oven to 350º. Grease and lightly flour two 9” round cake pans.
In a large bowl, combine cake mix, instant pudding, 1 cup sour cream, eggs, oil, ¾ cup water, and orange peel with an electric mixer on low speed for 1 min. Beat on medium speed for 2 min, scraping the bowl with a spatula. Pour evenly into prepared pans. Bake for 25-20 min or until toothpick inserted in center comes out clean. Cool completely.
Beat remaining 1/3 cup sour cream and powdered sugar in large bowl with whisk until well blended. Gently fold in whipped cream. Set aside.
Place 1 layer top side down on a platter, spread with half of the whipped topping. Top with ½ of the orange segments. Place the othr cake top side up on top. Spread the remaining whipped cream on top and garnish with remaining orange segments.
Refrigerate until ready to serve.