In a medium mixing bowl, combine the rolled oats, coconut milk, chia seeds, maple syrup, vanilla extract, and a pinch of salt. Use a whisk or spoon to stir thoroughly, ensuring all ingredients are well incorporated.
Carefully fold in the diced mango and shredded coconut, being gentle to retain the structure of the mango. If desired, set aside a small quantity of mango and shredded coconut to use as toppings.
Once mixed, cover the bowl tightly with plastic wrap or divide the mixture into individual jars with lids. Place in the refrigerator for at least 4 hours, preferably overnight, allowing the oats and chia seeds to absorb the liquid and soften.
In the morning, take out the oats and give them a good stir to break up any clumps. If you find the mixture too thick, simply add a splash of coconut milk until it reaches your desired creaminess.
To serve, scoop the oats into bowls or the jars you prepared them in. Top with the reserved mango, extra shredded coconut, and a sprig of fresh mint for a refreshing finish.