Place the dates in a heat-proof small container (I like a small glass measuring cup). Pour the boiling water over the dates and let soak for 5-10 minutes, or until the dates expand.
Combine the dates and soaking water, plus all the remaining ingredients in the carafe of a high-powered blender. Blend on high until smooth and no chunks of dates or spinach remain. Pour into two glasses and serve.
Notes
Use whatever milk you like (almond, cashew, soy, coconut, cow's, goat's, etc.), just make sure it is unsweetened and unflavored.