Add the sticky rice to your rice cooker and rinse until the water runs mostly clear. Drain, then add 1¼ cups of water. Cook using the White Rice setting.

While the rice cooks, combine the coconut milk, sugar, and salt in a small saucepan. Heat over low heat, stirring until the sugar dissolves. Do not let it boil. Remove from the heat and set aside.

Once the rice is finished cooking, gradually spoon about ½ cup of the warm coconut mixture over the rice, gently folding it in after each addition. Let the rice sit for 10–15 minutes so it absorbs the coconut milk.

In a small bowl, whisk together the cornstarch and 2 tablespoons of water to make a slurry.

Return the remaining coconut sauce to low heat. Stir in the cornstarch slurry and cook for 1–2 minutes, stirring constantly, until the sauce thickens.

Divide the sticky rice between serving plates. Top with fresh mango slices, drizzle with the thickened coconut sauce, and sprinkle with sesame seeds if desired.