Add sweet potatoes to the slow cooker and cover. Cook on high for 4 hrs or low for 8 hrs.
In a separate bowl, combine corn, beans, tomatoes, red onion, cumin salt, and cayenne pepper until well mixed.
Remove the potatoes from the slow cooker.
Cut each potato length-wise (about ¾ of the way through) and pull apart to open. Mash the inside of the potato with a fork.
Gently mix the corn filling evenly into the potato flesh and top with cilantro.
For added flavor, top with pico de gallo, guacamole, sour cream, or your favorite salsa.
Serve with tortilla chips for easy scooping!