To a small pot over medium heat, add the rice, pinch of salt, cinnamon sticks, whole cloves and water. Bring this to a boil, then lower to a simmer and allow to cook covered for 10-12 minutes.
Next, add the milks and vanilla extract, then stir to combine. Allow to simmer for 25-30 more minutes uncovered, or until it reaches your desired consistency.
Remove the pot from the stove and set aside to allow the arroz con leche to come to room temperature.
Once the arroz con leche has cooled, divide it amongst 8 small single-serving bowls, then combine the melting chocolate with the coconut oil in a small microwaveable bowl.
Place the bowl in the microwave and heat for about 2 minutes or until the chocolate has fully melted, stopping the microwave to stir every 30 seconds.
Divide and pour the melted chocolate over each bowl of arroz con leche, smoothing it over with the back of a spoon so that the chocolate sets in a thin, even layer.
Sprinkle a little flakey sea salt over each serving, if using, then pop them into the fridge to allow the chocolate to harden and set for at least 2 hours.
Once ready to enjoy, just crack the chocolate shell open with a spoon and dive in!