In a blender, combine all the flan ingredients: condensed and evaporated milk, cream cheese, eggs, and vanilla extract. Pulse high for 30 seconds until all the ingredients are combined.
Gently spoon the chocolate cake batter over the cajeta into the prepared cake pan and spread it out evenly.
Carefully pour the flan mixture over the chocolate cake batter, forming a layer of cake and a layer of flan. Don't worry if the cake and flan mix together a little because they will separate while baking. Cover with foil.
Place the cake in a roasting pan, then carefully pour about an inch of hot water into the pan.
Transfer the roasting pan to the oven, and bake for an hour until the surface of the cake is firm to the touch or a toothpick inserted in the center comes out clean.
Remove and let it cool to room temperature. Once it has cooled, wrap it in plastic wrap to prevent it from absorbing other flavors from the fridge.
Place in the refrigerator until the flan firms up, about two hours (but it will keep for four days).
Place a large pan or serving platter over the cake pan, grasp both together tightly, flip it over, and jiggle a little so it releases from the pan.
Remove the pan, scrape any remaining sauce from the bottom of the pan, and spread it on the cake.
Top with more cajeta and garnish with chopped pecans if desired.