Place peanuts, salt, and honey (if using) into a blender. Starting on lowest speed, blend mixture until crumbly, about 30 seconds to 1 minute. Increase speed and blend about 1 to 2 minutes, scraping down sides of blender with a spatula, until smooth and creamy.
Use spatula to scoop peanut butter into an airtight plastic container and keep refrigerated.
This recipe works best with a high-powered blender, such as a Vitamix or a Ninja, but a food processor will also get the job done (the nuts may take a bit longer to process).
We used dry-roasted, unsalted peanuts (find them in handy 16-ounce containers at most grocery stores) for convenience and nutrition. This variety contains no added salt or oils during the roasting process, all of which can add small amounts of sodium, calories, and fat.