This is super easy and I get asked for the recipe all the time. It is divine.
1 box triple chocolate cake mix
1 box instant chocolate pudding
1 cup sour cream
1/2 cup hot water
1/2 cup oil
3 TBS melted butter
1 16 ounce package milk chocolate chips
Combine all ingredients. Pour in VERY greased bundt pan. Bake on 350 for 50-60 min. Let sit in pan for 10 min then take out of pan. Serve with whipped cream, ice cream, caramel, raspberries or whatever you want.