Heat the oven to 175°C (350°F) and toast the peanuts for about 10 minutes. They will be ready when they are slightly glossy and golden. Skip this step if you are using pre-toasted nuts.
Transfer the still warm nuts into a food processor and blend until it forms a smooth and runny butter. If you are using pre-toasted nuts, there is no need to heat them, but you will have to process them for a few minutes longer to get the same results.
Preparation time is listed without the time used for peeling.