Recipe Instructions:
4 large egg yolks
200 milliliters (3/4 cup plus 2 tablespoons) full-fat coconut milk
30 grams (3 tablespoons) light brown palm sugar, finely chopped if crystallized*
65 grams (5 tablespoons) granulated sugar
3 fresh pandan leaves (you can find them in Asian stores; skip if you can't find them)
1 pinch fine sea salt
(all ingredients should be at room temperature)
Beat egg yolks with a fork until the yolks are combined (but don't beat them so much that they get foamy).
Heat coconut milk together with the chopped palm sugar, granulated sugar, pandan leaves, and salt in a double boiler or over a bain-marie. I always use a medium-size pot, filled with about 1 inch of gently simmering water, and place a heat-proof metal mixing bowl (e.g. stainless steel) over the pot.
Stir constantly with a rubber spatula as the coconut milk gets hotter. When the mixture comes to a boil (or at least nearly), remove the bain-marie (including the water pot) from the heat.
With a ladle, gradually (!) pour half of the hot coconut milk mixture (about 1/2 cup) into the egg yolks while constantly stirring the yolks. It is very important to do this slowly and while stirring, otherwise the yolks curdle easily. Also, if you remove the upper bowl from the bain-marie to pour the mixture, be careful not to get burnt, because the steam is very hot. That's why I use a ladle.
Put the bain-marie with the remaining coconut milk back on the stove and gradually add the egg-milk mixture while stirring.
Stir until the mixture thickens, about 10 to 20 minutes, depending on the heat. Don't cook it over high heat, as the yolks will curdle. The final texture should be custard-like, similar to that of lemon curd. The kaya will still get thicker once it cools.
Remove the pandan leaves and pour the kaya into clean jars. If you see any lumps or curdled egg, press the curd through a strainer first.
Keep coconut jam refrigerated and use within 1 week.
*Note: If you can't find light brown palm sugar, you can use 30 grams (3 tablespoons) dark brown palm sugar, or regular light/dark brown sugar instead.