Cooks' Note: Pandan, also known as Screw Pine, is used widely in Southeast Asian cooking as a flavoring and can be found in the Asian food section of some grocery stores or in Asian specialty stores.
In a sauce pot, mix all sauce ingredients together, then bring to simmer and cook over medium-low heat until sauce is slightly thickened. Leave whole pandan leaves in the sauce to steep and add flavor.
While sauce is reducing, brush grill grates with vegetable oil and heat to medium high. Give corn a little coating of sauce before it hits the grill, as the sugar will help caramelize the corn. Grill corn directly on the grates, turning occasionally, until cooked through and lightly charred, about 10 minutes.
Remove corn from grill and coat with more coconut sauce.
Spread a serving plate with mayonnaise and arrange corn over mayonnaise
Garnish dish with toasted coconut flakes and the sliced pandan leaves.