Beat butter and sugar until fluffy

Add in egg yolk one at a time while keep beating

Add in mixture of flour, BP and extract/juice

In a separate bowl, beat egg whites and lemon rind

Fold in egg white into batter and pour batter into prepared baking pan (am using half cylinder pan as shown)

Bake at preheated 350 F until toothpick comes out clean (about 25 minutes)

Take out from pan and cool on rack.

Mix agar-agar powder with milk and sugar in a pot.

Bring to boil, stirring continuously.

Place drained nata de coco, if using, on the base of your pan (the same shape for the cake).

Pour agar-agar mixture slowly, covering nata de coco, then place your cooled cake on top of it, and pour the rest of the agar-agar mixture (trim the cake a bit so it end and front would be covered by the pudding as well).

Let it cool a bit before firming it in the fridge.

Simmer milk, salt, and sugar, stir to dissolve

Before milk becomes too hot, take out a ladle or two, and mix it with yolk

Pour yolk mixture into the pot, stir continuously, and add in corn starch mixture

Once thickened, take off from heat and add in essences, stir to combine