Rinse sticky rice under cold water until the water runs clear. Soak for at least 1 hour or overnight. After soaking, drain and steam over simmering water for 20-25 minutes until tender and sticky.

Pour coconut milk into a saucepan and heat over medium-low heat. Stir in sugar and salt, mixing until dissolved. Cook for about 5 minutes, thickening slightly.

Once rice is cooked, transfer to a bowl and stir in half of the warm coconut sauce. Let it sit for about 10 minutes to absorb the flavors.

Heat a non-stick skillet over medium heat and add diced mango. Sprinkle brown sugar over the mango and cook for 3-5 minutes until caramelized. Add lime zest and juice, and cook for another minute.

Serve by spooning sticky rice onto a plate, topping with caramelized mango, drizzling remaining coconut sauce, and garnishing with mint leaves.