For the peanuts: Heat an iron kadhai or pan. Dry-roast the peanuts on medium to low heat until crisp (15-18 minutes).
Keep aside to cool for 20 minutes and gently remove the skin of the peanuts and make a fine powder in a mixer.
Arrange the peanuts in a microwave-safe flat dish and microwave at high (750 W) for 2.5 minutes.
Keep aside to cool.
Grease a steel plate with 1 tsp of oil/ghee and keep it ready.
For the jaggery syrup: Pour the melted and sieved jaggery and 1 tbsp of water in a thick bottomed non-stick pan. Boil on a low heat for 10-12 minutes, stirring continuously, until the mixture thickens and leaves the sides of the pan.
To test if the syrup is ready, drop a tsp of the hot jaggery syrup in cold water. If it forms a jaggery ball, the syrup is ready.
Mix the peanut powder and ginger powder with the jaggery.
Spread the mixture on the greased steel plate.
Apply 1 tsp of oil on both the palms and make small pedas or balls of the mixture while it's medium hot.