Drain the soaked cashews, and discard the soaking water. Add the drained cashews to a blender, along with 4 cups of fresh water, and the maple syrup and salt, if using.
Blend until smooth and creamy. If you have a powerful blender, there shouldn't be any cashew pulp to strain out. However, if you don't feel your blender got everything blended smoothly, you can pour the milk through a fine mesh strainer to catch any pieces that might have been missed.
Adjust the flavoring to your liking. You can add more maple syrup, or vanilla, if you'd like a vanilla-flavored milk. (See my tips in this post for making coffee creamer or chocolate milk.) Store the milk in an airtight container in the fridge for up to 4 days.
Nutrition information is for 1/4 of this recipe, which is a little over 1 cup of cashew milk. This information is automatically calculated, and is just an estimate, not a guarantee.