Place the peanuts on a baking sheet covered with baking paper, spreading them out well to prevent them from overlapping.
Bake for 10 minutes to lightly roast them, to enhance their flavor. Leave to cool later.
Place the peanuts in the bowl of a food processor. Mix on high speed for about 5 minutes. The peanuts will first turn into powder then into paste then into creamy butter. If the robot gets too hot, take breaks.
If desired, add a pinch of salt before the end of mixing.
Pour the peanut butter into a jar with a tight-fitting lid. To firm up the butter, place it in the refrigerator.
Notes
This peanut butter can be stored in the refrigerator for up to 1 month in its tightly closed jar.If the oil separates from the peanut butter over time, simply mix to return the original texture.