Roasting peanuts in a skillet is a time consuming affair. That's where the microwave comes to our rescue. Spread the nuts in a single layer in a microwave safe dish. For a crisp texture, nuke at HIGH for about 4-5 minutes under supervision. Cool for 5-10 minutes. I didn't remove the skins. You may do so if you like. It doesn't affect the taste.
Roast the sesame seeds in a deep skillet until they are aromatic and start popping. This will take around 3-4 minutes on a medium flame.
In a food processor, pulse the roasted peanuts first till you get an almost fine powder. Do the same with the sesame seeds.
Add all 3 ingredients together in the end and pulse for 2 minutes or so, until the natural oils are released and they come together.
Remove onto a plate. Add cardamom powder. Mix well and shape into balls of desired size. You don't need any extra ghee / fats to hold the laddoo together. The natural oils in the nuts and seeds do a great job of it. You could also roll them in dried coconut shavings for another layer of taste.