Preheat oven to 350 degrees. Grease and flour a 10-inch bundt pan.
In the bowl of a stand mixer, beat 1 chocolate cake mix, 1 3.4 oz. package instant chocolate pudding mix, 1 cup sour cream, 3 eggs, 1/3 cup vegetable oil, and 1/2 cup water until well blended. Fold in 2 cups semi-sweet chocolate chips.
Spoon batter (it will be thick) into prepared pan.
Bake for 50 minutes to 1 hour.
Cool for 15 minutes in the pan before turning out onto a wire rack to cool completely.
Once cooled, drizzle cake with Chocolate ganache, if desired.