Pre heat oven to 350 degrees. Grease and flour a 10 inch bunt pan.
In a large mixer bowl, combine cake mix, pudding mix, eggs, sour cream, and water. Beat on med speed for 2 minutes. Stir in chocolate chips. Spread batter in pan. Bake for 50 to 60 minutes or until a tester comes out clean. Cool on rack for 25 minutes. Then remove cake from pan and cool completely on rack.
2/3 cup chocolate chips melted
1/3 cup sour cream
Combine chocolate chips and sour cream stirring until smooth. Spread over top of cake. Cool to let frosting set.
(This can be done in a 13X9 pan. Bake for 40 minutes.)