To prepare the corn, place each ear upright in a bowl and firmly hold it in place. Use a sharp chef's knife to shave off the kernels along the length of the ear. Set the kernels aside.

In a pot, combine the corn cobs, pandan leaves (if using), and water. Bring to a boil, then cover, reduce heat, and let simmer for 30 minutes.

While the corn mixture is simmering, place tapioca pearls in a small bowl and cover with cold water, allowing them to soak.

Remove the corn cobs and pandan leaves from the pot and discard. Add coconut milk, corn kernels, sugar, and a pinch of salt to the pot, stirring to combine. Return to a boil and simmer until the corn is tender, which should take around 10 minutes. Taste and adjust sugar and salt as desired.

Stir in the soaked tapioca pearls and let simmer for an additional 2 minutes. Remove from heat and allow to cool. The dish can be refrigerated for up to 2 days, and if it becomes too thick, add water to thin it out.

Serve the sweet corn pudding warm or cold in bowls or glasses, and sprinkle with toasted sesame seeds just before serving.