After soaking the raw cashews overnight, pour off the soaking liquid and rinse them thoroughly under cool running water to remove any residual starch or bitterness.
Transfer the soaked cashews to a high-powered blender. Add the water, along with the maple syrup or honey, vanilla extract, and sea salt if you’re using them.
Blend on high speed for 1–2 minutes, or until the mixture looks completely smooth and creamy, with no visible cashew pieces left. If your blender is less powerful, you may need to blend a little longer and pause to scrape down the sides.
Once the milk has reached a silky consistency, pour it into a clean glass bottle or airtight container. Refrigerate until well chilled, and shake gently before serving, as some natural separation may occur over time.