Preheat oven to 350 degrees F (175 degrees C).
In a large bowl, mix together the cake and pudding mixes, sour cream, oil, beaten eggs and water. Stir in the chocolate chips and pour batter into a well greased 12 cup bundt pan.
Bake for 50 to 55 minutes, or until top is springy to the touch and a wooden toothpick inserted comes out clean. Cool cake thoroughly in pan at least an hour and a half before inverting onto a plate If desired, dust the cake with powdered sugar.
1 stick (1/2 cup) butter or margarine
2/3 cup HERSHEY'S Cocoa
3 cups powdered sugar
1/3 cup milk
1 teaspoon vanilla extract
Melt butter. Stir in cocoa. Alternately add powdered sugar and milk, beating to spreading consistency. Add small amount additional milk, if needed. Stir in vanilla. About 2 cups frosting.