Preheat your oven to 325°F/163°C. Then arrange the walnuts on a baking sheet and bake for 6-8 minutes. You only want to heat them up until slightly fragrant so be careful not to burn them, or your walnut butter will be bitter.
Remove from the oven and transfer the toasted walnuts to the bowl of your food processor. The walnuts will go through a few stages, from crumbled pieces, then flour, then it will start to lump together, and eventually, you'll have creamy, smooth walnut butter. Make sure to pause and scrape down the sides, as needed, and give your appliance small breaks in between processing so it doesn't overheat. The entire process (with breaks) will take about 3-5 minutes, depending on your processor strength.
Notes
Give your machine small breaks in between processing to prevent overheating. Turn off your food processor for 30-40 seconds at a time, as needed, and then continue. Use that break to scrape down the sides.Your homemade walnut butter will go through many stages, and it may feel like it’s never going to become butter, but it will. It goes from whole walnuts, to broken down pieces, to flour, to small clumps, then larger clumps, and finally creamy nut butter. (See process shots above for a visual.)For sugar free, skip the optional coconut sugar, or if you have a sweet tooth, increase to two tablespoons. (Try it with one first)You may use a high speed blender, such as a Vitamix for faster results, but I find it easier to scrape the nut butter out of a food processor bowl.