Every 5 minutes, remove the lid and stir gently with a stiff spatula
(not constantly) as the mix cooks VERY, VERY slowly to 80°C (175°F).

Place a flat plate beside the stove to rest your spatula and whisk (if
needed) – you will be doing a lot of stirring. If a little pool of kaya
accumulates on the plate, scrape it back into the bowl – every drop
is precious!
Take care that the mixture doesn’t overcook and look chunky on the
bottom of the bowl. If this does happen, remove the bowl from the
double boiler and hand whisk vigorously until the heat is regulated.

Then return the bowl to the double boiler and keep cooking to target
temperature.*

This slow cook takes around 30–40 minutes, and requires you to be the
conscientious custodian of your kaya. I time my kaya-making at home with
Kondo-ing my plastics cupboard or spice drawer.

When cooked, a spoon dipped in will be well coated and if you draw
your finger across the back, it will leave a clean trail. If you shake
the spoon, the clear trail will remain intact. Remove the lid and bowl
from the double boiler and cool, stirring gently and occasionally
until lukewarm. Cover the top closely with plastic wrap (or scrape
into a sterilised jar) and chill until ready to fold through your Toasted
coconut + kaya tres leches topping (page 169).**

If you’d like a thicker, spreadable when chilled consistency, cook for a further
10–15 minutes until thick like a thick lemon curd.

* If the mix has co ttage-cheesy chunks after it steams, cool for 5 minutes, then
whiz in a food processor. It will become smooth again just like magic, albeit
a  little less thick.

** If the chilled kaya is too thick (like peanut butter), soften it by warming gently
over a double boiler and adding enough of the remaining coconut cream to
loosen it up.