Grate the mawa or make crumbles using your fingers. Priya's tip - If using store-bought mawa, bring it to room temperature first, and then use it.
Add ghee to a pan once it melts, and add the grated khoya. Cook on a low flame. Khoya will begin to melt. Keep stirring it. Priya's tip - if the khoya feels drier than usual (varies by brand/batch), add a splash of milk while cooking to loosen it.
Add sugar to the pan. Continue to sauté for 1-2 minutes or till the sugar melts.
Add the chopped nuts along with the saffron strands.
Now add cocoa powder using a sieve to prevent lumps from forming. Give it a good mix.
Eventually, the mixture will no longer stick to the pan and will come together like a soft dough. Priya's tip - Do not overcook, or the chocolate modak will turn out dense. Take it off the flame. To check its doneness, roll the hot mixture into a tiny ball. It should form a ball easily.
Carefully transfer this chocolate modak mixture to a greased plate. Allow it to cool down completely. You can also pop it into the fridge for 10 minutes. Meanwhile, grease the molds with ghee, butter, or oil. Priya's tip - If the modak mixture feels too soft and is not pliable, add a spoonful of milk powder or almond flour, mix and chill.
Stuff each side of the mold generously with the mixture.
Close the modak mold and press it tightly. Remove any excess. Open the mold and carefully remove the modak. Priya's tip - If it doesn't come out as clean as you would want, you can always adjust the shape by pinching the top with your fingers to sharpen the point. Do it immediately after unmolding, before it fully sets.
Place it on your serving platter. Repeat until you finish making all the modaks. Priya's tip - Grease the mold with ghee every time before stuffing.