Crush rock sugar into smaller pieces, add some water, and cook over low heat until syrup stands when picked with a chopstick. Turn off heat.
Roast crushed peanuts in a pan with only a little oil. Fry until fragrant, and stir into syrup.
Slightly grease a baking pan, pour in syrup and peanut mixture and let cool. When cooled thoroughly,cut into small pieces with a knife.