1. Mix all ingredients for glutinous rice base together and steam for 20 minutes. Stir it half way through.
2.Cut pandan leaves into small pieces, blend with water and strain to discard fibers. Add a few drops of food colouring into the extract if desired.
3.Dissolve sugar in hot water and set aside to cool. Beat eggs in a bowl and pour in cooled syrup and 100ml of pandan extract.
4.Whisk in custard powder, plain flour, tapioca flour and coconut milk. Strain to remove lumps. Cook on medium heat until slightly thick. It should lightly coat the back of a spoon.
5.Once glutinous rice is cooked, compact it down with a banana leaf or a wet spoon. Steam again for another 3 minutes.
6.Pour pre-cooked custard onto the hot glutinous rice and steam on medium-low heat for 25 minutes until custard has set.
7.Allow Serimuka to rest for at least 2 hours in room temperature before cutting.