In a medium bowl, whisk the yellow cornmeal with 1 cup of cold water until completely smooth. This crucial step prevents lumps from forming when the cornmeal hits the hot liquid.

In a medium saucepan, bring the remaining 3 cups of water and the cinnamon stick to a rolling boil over medium-high heat. Let it boil for about 2 minutes to infuse the water with warm cinnamon flavor.

Reduce the heat to medium-low and slowly pour the wet cornmeal mixture into the boiling water while whisking continuously. Keep whisking for about 3 minutes as the mixture begins to thicken significantly.

Cover the saucepan and let the porridge simmer gently on low heat for 12 to 15 minutes. Stir every 3 to 4 minutes to ensure the bottom does not burn, cooking until the cornmeal is tender and no longer grainy.

Remove the pan from the heat and stir in the sweetened condensed milk, evaporated milk, freshly grated nutmeg, vanilla extract, and salt. Mix thoroughly until the porridge is rich, creamy, and uniform in color.

Ladle the hot porridge into bowls while it is still perfectly creamy. Serve immediately with an extra splash of evaporated milk and a pinch of cinnamon on top for a beautiful and delicious finish.