Cashews are highly perishable and can turn rancid quickly due to their high oil content. Choose vacuum-packed jars or cans over cellophane packaging. Store cashews in a cool, dry place in an airtight container to avoid absorption of other food odors. Cashew butter can be used in place of peanut butter or as an ingredient in cookies, spreads or other dishes. If desired, substitute peanuts for the cashews to make Homemade Peanut Butter.
In a food processor or blender, combine the nuts, 2 tablespoons of the oil, the salt, and the sugar, if desired. Process on high speed for 30 seconds. Scrape down the sides with a rubber spatula and process to desired smoothness, adding more oil, 1 teaspoon at a time, if a smoother butter is desired. Adjust the seasoning, to taste.
Transfer to a bowl to use as a dip, spread, or in other recipes, or place in an airtight container and refrigerate until ready to use.