Uncle John always had this for his birthday cake.
1 yellow cake mix, baked according to pkg.
2 small pkgs. instant chocolate pudding
1 C. powdered sugar
4 C. cold milk
Add sugar to pudding, Slowly add milk. Beat 1 minute. Pour 1/2 over warm cake (holes). Let half of mixture thicken for topping. Chill for 1 hour.