Turn on the steamer first.
Grease the mold in which the custard is going to be cooked. Keep aside.
In a mixing bowl take grated jaggery along with cinnamon powder, cardamom powder, nutmeg powder.
Using a hand whisk, mix well everything first.
Then pour the coconut milk and whisk again till everything is well incorporated.
After that, add the corn flour and gently mix using the hand whisk.
If the mixture seems little thick in consistency, then add 1 tbsp water little by little.
Pour the mixture into the greased molds.
Cover the molds with aluminium foil and steam for 10-12 minutes.
Take out the molds from the steamer and allow to cool down.
Then keep in the refrigerator till serving.
Meanwhile, start making the cashew praline.
For this, first line a parchament paper over a plate. Keep aside.
Now heat sugar in a saucepan over medium heat.
Soon the sugar will start to completely melt down, then add the cardamom powder.
The color will change to amber, immediately turn off heat and add the cashews.
Mix quickly everything and transfer the mixture onto the plate lined with parchament paper.
Immediately try to spread the mixture as much as possible using a spoon or knife.
When it cools down, then it will become so hard.
Now break it with the help of rolling pin and cashew praline is ready.
While serving the watalappan, just top with some cashew pralines and serve !