Pre-heat oven to 350ºF (180ºC).

Grease a 12-12.5 cup (about 2.8 liters) Bundt pan with either cooking oil or softened butter.

Place the dulce de leche or caramel in the bottom of the pan. Set aside.

Prepare the cake mix according to the instructions of the package. My box indicated to mix all the ingredients in a large bowl.

Pour the cake batter over the dulce de leche or caramel that was placed in the Bundt pan.

In a blender, blend all the ingredients for the flan until smooth.

Slowly pour the flan mixture over the cake batter.

Cover the Bundt pan with aluminum foil and place it inside a large roasting pan. Then, pour in the hot water into the roasting pan until it comes halfway up the sides of the Bundt pan.

Bake for 1 hour, then remove the aluminum foil and cook for another 15-30 minutes or until a toothpick inserted in the middle of the cake comes out clean.

Remove the Bundt pan from the oven and let the chocoflan cool completely on a wire rack.

Once it's cool place a serving plate over the cake and flip it over. Serve with extra dulce de leche or caramel.