1. Rub the dry sticky rice gently with the piece of alum using your hands. This helps make the rice shiny and translucent.

2. Add water to the dry sticky rice until the water level is about 1.5 inches above the rice. Gently rub the rice again with the alum, being careful not to break the grains. Continue until the water turns cloudy white, then pour off the water. Rinse the sticky rice 4 times, or until the water runs clear. Add clean water to cover the rice by 2–3 inches and soak for 3 hours (you can also soak it in pandan leaf water). Once soaked, drain the rice well and transfer it to a steamer basket. Fill a pot with water and add pandan leaves, then steam the rice with the lid on for 20 minutes or until tender.

Toast the sesame seeds until fragrant.

Prepare the coconut syrup for the sticky rice: Pour the coconut milk into a brass pan, add 2 teaspoons salt and 2 1/2 cups (about 500 grams) sugar. Heat gently, stirring until the sugar dissolves, making sure the coconut milk doesn’t separate. Add fresh pandan juice until you reach your desired color.

When the sticky rice is fully cooked and still hot, immediately transfer it to the coconut syrup. Stir with a spatula to let the coconut syrup absorb into the rice. Cover tightly and let sit for 10 minutes. Uncover and stir again, then cover and let sit for another 20 minutes. Stir once more, cover, and let sit for a final 10 minutes. The sticky rice should now be glossy and ready to serve.

To make the coconut topping: Pour the coconut cream, salt, and rice flour into a saucepan. Cook over low heat, stirring until the mixture thickens and the flour is cooked through.