In a medium saucepan, combine water, milk and vanilla.
Bring to a boil.
Meanwhile, combine the masa harina, salt and cinnamon in a medium bowl.
Add the remaining ½ cup of water to the mixture, a little at a time, until you have a smooth paste.
Reduce heat to low and add sweetened condensed milk to the pot and stir to combine.
On low heat, slowly add the thick cornmeal paste with a whisk, while stirring constantly to avoid any lumps.
Continue cooking at a low simmer for about 10 minutes.
Using an electric mixer, beat the eggs until light and fluffy – about 10 minutes.
Add the eggs to the conrmeal a little at a time, mixing well after each addition.
Place the mixture in a square baking dish or in individual ramekins.
Now you must prepare the water bath.
Place the pan in a larger baking dish and add boiling water in the larger dish to reach halfway up the sides of the square baking dish.
Bake for 1 - 1 1/2 hour, until the custard is set.
Chill overnight in the refrigerator.
To make the chocolate sauce, heat the cream with the espresso powder and the vanilla.
Turn off the heat and add the chocolate. Stir to combine and leave it to rest for 5 minutes.
Add the butter and salt and mix well until smooth.