Soak cashews in water for at least 30 minutes, ideally for at least 2 hours. If I know I am going to use cashews for dinner, I will place them in water either at night or in the morning before work.

Drain and rinse cashews.

Place in a high-powered blender with 1/2 cup fresh water and pinch of salt (if using) and puree until very, very smooth. (In my Blend-Tec, this takes about 1 minute, in older blenders it may take up to 5)