Place pistachios, water and dates in a closed container to soak overnight.
Strain nuts and dates from water and place in a blendtec and discard old water. Add 3 cups of fresh, cold water to the blender along with vanilla and stevia.
Blend for 1-2 minutes at highest speed, until smooth.
Place a nut milk bag OR two layers of cheesecloth in a large bowl then slowly pour the milk into the bag.
Close and gently squeeze bag until all liquid has come out. Place milk in a closed container and in fridge.
Notes
Feel free to use the pulp for a nut meal for cookies or baking!