Place the cashews in a bowl, cover with water, and soak overnight or for at least 6-8 hours.
Drain and rinse the cashews well to remove the soaking water.
Add the cashews to a blender along with the plant milk and maple syrup.
Blend on high for about 3 minutes until completely smooth and creamy, scraping down the sides as needed. If your blender has a nut butter setting, use that.
Add more plant milk a little at a time if needed to help it blend, until you reach your desired consistency.
Add a pinch of cardamom if using and blend briefly to combine.
Taste and adjust sweetness with a little more maple syrup if you like.
Store in an airtight container in the fridge for up to 5 days.