How to prepare the filling: Blend corn kernels in a liquidiser until finely mashed; cook together with sugar, salt, agar-agar powder and hoen kwe flour in a medium saucepan. Keep stirring until mixture turns thick.
Leave to cool slightly. Take half a teaspoonful and roll into a small ball. Refrigerate the balls of filling.
How to prepare angku skin: Put corn kernels and pati santan in a liquidiser and blend into a fine paste. Strain the paste and discard the impurities.
Mix strained mixture with agar-agar powder, instant jelly, salt, sugar, colouring and water. Blend well and cook in a deep saucepan over a medium flame until bubbles appear. Stir in hoen kwe mixture; keep stirring and cook until mixture comes to a boil. Chill the plastic angku moulds well in ice-cold water or chill them well in the freezer compartment of the refrigerator for a couple of hours before use.
Pour mixture two-thirds full into chilled plastic angku moulds; add a ball of filling and top up with more agar-agar mixture. Set aside to cool slightly, then chill in the freezer compartment until jelly is fully set. Ease out jelly from the mould and keep jellies chilled in the refrigerator until serving time.