I got this recipe from a great blog that I follow called Little Birdie Secrets. This is really as rich and easy as it comes - just don't forget the extra milk to drink with it! I think it's best within a few hours out of the oven while the chocolate chips are still melted and gooey, but it's also great cold too!
1 chocolate cake mix
1 small package (3.4 ounce) instant chocolate pudding
1 cup milk
1/2 cup sour cream
2 cups semi sweet chocolate chips
1 cup chocolate chips
3/4 cup heavy cream
1 teaspoon vanilla
1. Preheat oven to 350-degrees. Grease and flour or spray bundt pan.
2. Mix all of the ingredients, except chocolate chips, together until well blended. Stir in chocolate chips.
3. Pour into prepared pan and bake for 55-65 minutes.
4. While the cake is baking, make the ganache by combining chocolate chips and heavy cream over medium heat. Bring to a boil, then remove from heat and stir in vanilla. The ganache will thicken as it cools while the cake continues to bake.
5. After the cake has finished baking, allow it to cool for 10 minutes before turning out onto a plate or platter. Glaze with chocolate ganache.