Take peanuts in a baking tray. Preheat oven to 150 degrees. Set timer to 15 minutes.
Toast the peanuts till they begin to crackle and turn golden.
Or, take peanuts in a thick bottom wok. Roast till they crackle and become golden. Keep stirring during the process of roasting. Let the roasted nuts cool.
Take oats in a thick bottom wok. Roast on medium flame till they become slightly crisp and the colour just begins to change. Let the oats cool.
Take cold roasted nuts in a grinder and grind them to get a fine powder. Do not grind for too long.
Grind oats to a fine powder.
Transfer ground nuts and oats to a deep bowl. Mix well.
Take crumbled jaggery and add to the mixture. Mix with hands. Break lumps of jaggery if any.
Take a handful of mixture and shape into ball pressing the mixture tightly with your fingers. Use only one hand to shape laddu.
In case if the mixture seems a bit dry, add more jaggery.
Store in an airtight container.