Step 1

Slice the sponge cake horizontally into 2 or 3 slices (depends on how many layers you want). Try to cut as flat and evenly as possible

Step 2

Don't trim the 4 edges of the cake. I did a mistake by doing that and the custard ends up being not enough for a 3-layer cake because too much gap on the 4 sides that have to be filled with custard

Step 3

Cut the pandan leaves into small pieces. Put them inside a blender along with water and coconut milk and blend until smooth. Strain the mixture and make sure it measures 350 ml total. You can top up with some water to make up for the amount if needed

Step 4

Add hun kwe flour to the pandan coconut milk mixture and whisk to combine

Step 5

In a heavy bottom pot or saucepan, add water, sugar, salt, and agar agar powder. Stir to combine. Let them sit for 20 minutes. The agar agar will dissolve better later

Step 6

Put the pan on low heat, add butter, and cook until the agar agar dissolves. You shouldn't see anymore specks of agar agar. If they don't dissolve, your kaya custard will not set later

Step 7

Remove from the heat and add pandan coconut mixture and stir to combine. Return it back to the stove and cook over low heat until the mixture thickens slightly and coats the spatula but still liquid and pourable

Step 8

Rinse the clean pan you use to bake the cake with water and then shake off excess

Step 9

Pour in about 300 gr of kaya custard (for 3-layer cake) or 400 gr for 2-layer cake. Gently put first layer of cake on top and just gently press the cake down a little bit. Pour in second layer of custard, then top with second layer of cake and pour the remaining kaya custard if you are making 2 layer-cake. For 3-layer cake, top with the third layer of cake and finish off with the rest of the kaya custard

Step 10

Let the cake cools down at room temperature and then transfer to a fridge to let it cool for 5 to 6 hours or overnight

Step 11

Gently turn the cake upside down onto a serving platter. Wrap the side of the cake pan with a hot towel. It helps to release the cake. You can also roll the cake pan on its side gently and because of gravity, it will help to loosen the cake from the side and it will slide out later

Step 12

You can decorate it if you like, I didn't, I just serve it as is

Step 13

It is best to finish the cake in about 3 days. I noticed that after 3 days, the custard starts to ooze out some liquid making the cake a bit wet. This is typical for agar-agar type of cake or custard