Place heavy iron skillet (Note: This is the only utensil that should be used for this recipe.) over medium heat.
Put sugar and stir constantly until sugar melts and becomes syrupy. Don't let it turn dark brown.
Sugar will form some hard pieces before melting and possibly some lumps will not melt.
This is OK. Before sugar becomes too dark, add pounded peanuts and butter.
Stir thoroughly until nuts are coated. Then spread mixture on flat cookie surface or cookie sheet.
Flatten as thin as possible. Cool. Break into serving pieces.