1. Preheat oven to 350 degrees F. Grease and flour a 9" Bundt cake pan and set aside.
2. In a large bowl, combine cake mix with pudding mix, and whisk with a fork to remove any lumps.
3. Add milk, sour cream and 4 eggs; beat on a low-speed with an electric mixer, just until moistened.
4. Increase speed to medium and beat the batter for about a minute. Stir in baking chips by hand. Pour batter into prepared cake pan and bake in heated oven for 55-65 minutes. (I cover it loosely with foil, mid-way through baking time, to keep the color of the cake a light golden hue.)Test with a toothpick, and let cool for at least 15 minutes on a wire rack. Flip pan over to remove cake, and serve warm, with a "cool whip" frosting if desired.