Preheat oven to 325 degrees F (165 degrees C). Grease and flour a 10 inch Bundt pan.
In a medium bowl, stir together the cake mix, instant pudding and sugar. Add the water, oil, eggs, and sour cream, mix until well blended. Finally, fold in the chocolate chips. Pour into the prepared Bundt pan.
Bake for 50 to 60 minutes in the preheated oven. Cake is done when a toothpick inserted comes out clean. Cool in pan for 10 minutes before inverting onto a wire rack to cool completely. Dust with confectioners' sugar before cutting and serving.
