Preheat the oven to 350 F/176 C. In a large bowl combine the eggs, oil, and water and whisk them together.
Add the cake mix to the bowl and blend it in. Or follow the directions for a homemade chocolate cake batter.
Pour about a fourth of a cup of caramel sauce on the bottom of a bundt cake pan that has been greased with butter or shortening. Then pour the chocolate cake batter on top of that.
Time to make the flan. You can't have chocoflan without flan. In a blender add the room temp eggs, sweetened condensed milk, and evaporated milk and blend for 30 to 40 seconds until well combined.
Pour the flan over the cake batter.
Place the pan in a roasting pan and add about an inch deep of hot water to the roasting pan. Cover the bundt cake with aluminum foil.
Bake the cake for 60 minutes. Then remove the foil and check it with a toothpick. Most likely it won't be done yet. Replace the cake in the oven and continue baking for 15 to 20 minutes with the foil off.
Once the cake is done allow it to cool in the pan at room temp for one hour. Then place it in the refrigerator to cool for at least 4 hours. Now slice into it and eat it! Enjoy!