This is one of our favorite cakes, moist and full of flavor. The recipe comes from "The Cake Mix Doctor" book by Anne Byrn. Her recipes use cake mixes to make great desserts, with that made-from-scratch taste! A really wonderful cookbook!
Place rack in the center of the oven and preheat to 325'F. Spray a 10" tube pan (or three 8" loaf pans) with cooking spray, then dust with flour. Shake out excess flour and set aside.
Break the German chocolate bar into four pieces. Grate the bar using a food processor or a hand grater until it is finely grated. (If using a food processor, insert the steel blade and drop the chocolate pieces into the processor one at a time.) Set aside.
(Time-saver tip- I found out, recently, that you can also melt the chocolate, and I'm thinking this has got to be easier!)
Place the cake mix, pudding mix, milk, oil, and eggs in a large mixing bowl. Blend with an electric mixer on low for 1 minute. Fold in the grated chocolate, and scrape down the sides of the bowl with a rubber spatula. Increase the mixer speed to medium and beat 2 minutes more scraping the sides down again if needed. Fold in the chocolate chips. The batter should look well blended and the chocolate chips should be evenly distributed. Pour the batter into prepared tube pan (or loaf pans), smoothing out with the rubber spatula. Place pan in oven.
Bake until golden brown and the center springs back when lightly pressed with your finger, 55-58 minutes for tube pan (50-52 minutes for loaf pans). Remove from the oven and place it on a wire rack to cool for 20 minutes for tube pan (5-8 minutes for loaves).
Run a long, sharp knife around the edge of the cake and invert it onto a rack, then invert it again onto a cake/serving plate so it is right side up. Allow to cool 30 minutes more. Dust with confectioner's sugar if desired.