Brush a 1.5-2L rectangle or square baking pan or 3 llaneras with butter or oil. Set aside.
In a large bowl, sift together rice flour, glutinous rice flour, sugar, and salt.
½ cup rice flour, 1 cup glutinous rice flour, ½ cup sugar, ½ teaspoon salt
Take ½ cup of coconut milk and set it aside. Pour the remaining coconut milk into the dry ingredients. Mix until well blended.
2 cans coconut milk
Transfer to a pan and turn the heat to medium. Stir regularly until it becomes a thick sticky paste. Add the vanilla extract and then turn the heat off.
1 teaspoon vanilla extract
Take about ½ of the mixture and transfer it to a bowl. Add the ube halaya to the bowl and mix. Add some drops of ube flavor as needed.
½ cup ube halaya, 3-4 drops ube flavour
Transfer this to the prepared baking dish or divide it equally among the llaneras. Grease a spatula with oil and use this to spread and even out the mixture if too sticky.
Add the remaining white paste on top spreading it out evenly.
Add 1 tablespoon sugar and ½ teaspoon rice flour to the reserved ½ cup coconut milk. Heat in the microwave or stove-top just until warm enough to dissolve the sugar.
1 tablespoon sugar, 1 teaspoon rice flour
Pour this on top of the cooked mixture.
Place on the highest rack of the oven and bake at 200ºC/400ºF until the top becomes bubbly and brown spots form.
Remove from oven and let it cool down a bit before serving.