A high-powered blender works best. While you can make cashew cream in a food processor, it won't get as smooth as it does in a high-powered blender, like a Vitamix, Blendtec, Ninja, etc. It will also take longer to blend (about 4-5 minutes instead of 2 minutes).  A standard blender would be your last resort, and it'll never be perfect—you'll have little cashew bits in your cream. If you are using this, I'd recommend soaking your cashews overnight, rinsing them, and soaking them again in fresh water. A long soak is really necessary for blenders without a powerful blade.  Typically, refurbished blenders are sold at a significant discount, like this Vitamix.