Add purple potato powder and maple syrup. Heat on stovetop on medium, whisking the whole time to combine.
If you don't have a milk frother, pour it into a mason jar with secure lid. Cover with a towel if necessary. Shake to combine.
Pour into a mug.
Notes
Do NOT use a Nutribullet to blend hot soy milk. It doesn't do well with hot liquids. You can blend cold ingredients in a Nutribullet (or a high-speed blender, just heat it after blending.I used soy milk because it froths nicely. You can use any plant-based milk you like.Shake in a mason jar if you want it frothy and don't have a milk frother.