Mix coconut, cardamom powder and jaggery in a pan. Begin to cook on a low heat. If using desiccated coconut add 2 tbsp water for the jaggery to release moisture, skip water if using fresh coconut. If your jaggery isn't clean, then you can melt it with 2 tbsp water and filter it. Then add coconut to it and cook until the mixture thickens.
When the mixture thickens, switch off the heat and cool this.
Divide the mixture to 9 to 11 portions and roll them to balls.
On a low to medium heat , roast semolina in 1½ tablespoons ghee until crunchy and aromatic.
While you roast the rava, bring water to a boil.
Lower the flame. Pour this slowly to the semolina stirring with the other hand to prevent lumps.
Stir well to make sure there are no lumps. Add salt or sugar. If you want you may add another tbsp of ghee at this stage.
Cover and cook until the water is completely absorbed. Cook for another 2 mins until the mixture is fully cooked.
Cool this down. Grease your palms and knead it a bit to make the mixture smooth and uniform.
Grease the mould and stuff the rava mixture. Make a large hole in the center and stuff the ball. Seal them. Repeat greasing and the other steps to make more. (Check the stepwise pics)
Rava modak are ready to offer God Ganesha.