Boil a peeled and roughly chopped sweet potato with the pitted Medjool dates, maple syrup, cinnamon, nutmeg, and salt in a saucepan with half a cup of water.
When the sweet potatoes are fork tender, turn the heat off and add the vanilla extract. Transfer everything in the pan into a high-powered blender. Blend for 2 minutes on high speed, or until completely smooth.Optionally, strain the purée through a fine mesh strainer if it's gritty.
In a tall glass cup, spoon in 2 tablespoons of the sweet potato puree. Pour the shot of espresso in and mix the puree and espresso together.