Mix the powdered jaggery with the coconut in a heavy pan or kadai.
Keep the pan or kadai on a low heat. Stir the mixture often.
The jaggery would start melting at first. Later it will continue to cook.
Cook this filling mixture till the jaggery starts thickening. It should not have any liquids in it. Once the mixture has cooked then add the cardamom powder and mix well.
Don't over cook as then mixture would become dense and hard.
Keep aside for cooling the filling. Note that as the filling cools it will thicken.
Making rava dough
Take water in a saucepan or any pan. Add oil and salt in it.
Bring the water to a rolling boil. When it comes to a rolling boil then switch off the heat and place it on the kitchen countertop.
Add the semolina or rava to the hot water.
Stir with a wooden spatula or spoon till all the semolina has been incorporated in the water.
Mix really well. Now keep this pan on low heat for 5 to 6 minutes.
Continously stir so that the rava does not stick and get burnt.
After five minutes switch off the heat.
Taste a pinch of the dough. (only if you are making this for your family and not for Bhagwan Ganesha).
If the semolina feels undercooked, then cook for a few more minutes. Ensure that the rava is cooked well and not undercooked.
Cover the pan with a lid for 5 to 6 minutes.
The dough would be still hot when the kneading has to be done.
If you cannot manage the heat, then let it cool for a few minutes more.
Knead well and make a smooth dough.
When kneading apply some oil on your palms. There should be no lumps in the dough after kneading.
Making rava modak
Now take a lemon sized ball from the dough.
Flatten the dough ball on the palm of your hands or with your fingers.
Place a few spoonsfuls of the coconut-jaggery filling in the center.
Pinch the edges and bring the fluted edges in the center.
Join the center and pinch off the top. Taper the top.
Make the rava modaks in a similar way.
You don't need to steam them further.
Serve rava modak to Bhagwan Ganesha.
If the outer semolina cover tastes a slight undercooked even after making the rava modaks, then just microwave the prepared rava modaks for a minute or so till they are cooked. Or you can steam them for 2 to 3 minutes in a pan on the stovetop.
Use finer variety of rava.
If the rava mixture looks dry and loose then add a few tablespoons of hot water to it.