Preheat oven to 350’. Grease and flour 13 x 9 x 2 inch pan. Prepare cake mix according to package directions. Pour batter into prepared pan. Mix cheese, eggs, sugar and vanilla. Gently pour on top of cake mix. Bake 1 hour or until tester comes out dry. Cool.
Mix pudding and milk using hand mixer at medium speed. Add Cool Whip and beat on high with mixer until creamy. Spread on cake. If desired, shave a chocolate bar with a potato peeler over the topping.