Red Bean Filling: Wash and soak red beans for half an hour. Drain and cook the red beans in some water for 30 minutes, or until soft. Drain and puree the red bean with 2/3 cup water. Set aside.
In a pot, bring water, jelly powder and pandan leaves to a boil. Add in red bean paste, coconut milk, custard powder, salt and coloring and bring to a quick boil, stirring continuously with a hand whisk. Once mixture starts to bubble, turn off heat.
Pour into a 15cm (6”) square tray/pan. Divide the square into nine imaginary smaller 5cm (2”) squares and drop a jelly yolk in the centre of each square. Allow to set completely before chilling in the refrigerator for another 30 minutes.
Cut into nine 5cm (2”) squares and set aside for filling the mooncakes.
Pink Jelly Skin: In a pot, bring the first four ingredients to a boil.
Lower heat and add the rest of the ingredients, stirring continuously with a hand whisk until the mixture starts to bubble. Turn off heat immediately.
Pour a ½ cm layer of the pink jelly skin mixture into a square jelly mooncake mould. Allow to cool until almost set (3/4 set). Place prepared red bean filling in the centre of the mould.
Top up with pink jelly skin mixture and allow to set completely before chilling in the refrigerator for another 30 minutes.
Unmould red bean jelly mooncake and keep refrigerated until ready to serve.