Add the peanuts to a baking tray, season with a pinch of salt and bake in the oven for 10 minutes, until toasted. Stir occasionally while cooking.
Once toasted, leave to cool for at least 10 minutes.
If making crunchy peanut butter, take approximately 1/6 of the peanuts and pulse in a food processor until ground but not powdered. Set aside until later.
Next, add the remaining peanuts (or all peanuts at once, if making smooth peanut butter) to the food processor bowl and pulse for one minute. Scrape down the sides with a spoon or spatula and continue to pulse for another minute or two, until the peanuts are completely ground and combined.
Season with salt, to taste, and add one teaspoon of oil if need be, to loosen up the peanut butter. At this point, add honey to taste, if using. Pulse for another minute and add more oil if necessary, one teaspoon at a time.
If making crunchy peanut butter, fold the crushed peanuts into the peanut butter mixture at this stage.
Transfer from the food processor to a suitable container. Peanut butter will last for at least a month in the fridge.