At first, preheat the oven before baking and set the temperature at 375℉. Grease a 9-inch round baking pan.
Wash and scrub the purple sweet potatoes to get them cleaned properly. Peel the sweet purple potatoes and chop them into cubes.
Using a high-speed blender, add coconut milk, coconut palm sugar, spices, salt, and purple sweet potatoes.
Pulse the blender until sweet potatoes are finely pureed. Transfer the mixture to a large bowl.
Stir in the flour to make a perfectly smooth batter.
Pour the batter into the baking pan and bake it for at least 75 minutes.
Mix all the custard topping ingredients in a small bowl and pour them equally on the top of the pudding.
Return the pudding to the oven and bake it for another 15 minutes, until the top gets a golden brown texture.
You can serve this delicious pudding alone, or add some coconut whipped cream on top.