Pierce each potato 3 or 4 times with a sharp knife and place on a microwave-safe plate. Heat in the microwave until cooked through, 6-7 minutes. (Alternatively, bake in the oven for 45-60 minutes at 350 degrees F.)
While potatoes are cooking, mix together black bean salsa but combining all remaining ingredients in a medium bowl: black beans through cayenne. Toss well and check for seasoning. Adjust accordingly.
To serve, slice open each sweet potato and stuff with equal portions of the black bean salsa.
Top with additional cilantro and any other garnishes you wish such as plain yogurt, hot sauce or even a fried egg.