Rinse the Arborio rice under cold water until the water runs clear to remove excess starch.
In a medium saucepan, combine the rinsed rice, coconut milk, almond milk, sugar, and salt. Bring it to a gentle boil over medium heat, stirring occasionally.
Once boiling, reduce the heat to low and cover the saucepan. Simmer for about 20 to 25 minutes, stirring frequently to prevent sticking, until the rice is creamy and tender.
Remove the saucepan from heat and stir in the vanilla extract and ground cinnamon. Allow it to sit covered for an additional 5 minutes to thicken further.
Serve the rice pudding warm or chilled in individual bowls, topped with fresh mango slices and a sprinkle of toasted coconut flakes for added texture.