Blend the peanuts: Add the peanuts (and a pinch of salt, if your peanuts are unsalted) to a food processor. Blend for 2-5 minutes, scraping down the sides as needed, until it becomes smooth and creamy. It may take longer depending on how powerful your food processor is. Be patient - it will get there!
Store and enjoy: Once smooth and creamy, transfer your homemade peanut butter to small glass jars. Store in the pantry for up to 1 week, or in the fridge for up to 1 month. This recipe yields about 2 cups of peanut butter.
Notes
Use roasted peanuts: It helps release oils faster for a creamier texture. You can buy roasted peanuts, or roast them yourself on a baking sheet at 350°F for 10 minutes.
I recommend using a food processor: A high-powered blender (such as a Vitamix) can work, but I think a food processor is much easier.
Be patient while blending: The peanuts will go from crumbly → thick → clumpy → smooth. Just keep blending, it can take 2-5 minutes depending on your food processor. And be sure to scrape down the sides - it keeps everything blending smoothly.
Add flavorings: Add your favorite flavorings (such as cinnamon, vanilla, or maple syrup) after the peanut butter becomes smooth and creamy. It may clump again, but keep blending. It will turn smooth and creamy again.