Rinse 1 cup of sticky rice under cold water until the water runs clear. Soak it in a bowl of water for 1-2 hours or overnight.

Drain the rice and transfer it to a heatproof bowl or bamboo steamer. Steam for about 20-25 minutes, until soft and sticky.

Combine 1 cup of coconut milk, 1/4 cup of sugar, and a pinch of salt in a saucepan. Heat over medium-low until sugar dissolves.

For a thicker sauce, mix 1 tablespoon of cornstarch with 2 tablespoons of water and add to the saucepan while stirring.

Combine the cooked sticky rice with about 1 cup of the coconut sauce, folding it gently until well mixed.

Scoop portions of the sticky rice into bowls, slice the mangoes, and arrange beside the rice. Drizzle with remaining coconut sauce and sprinkle with sesame seeds.