Preheat the oven to 400°F (200°C). Scrub the sweet potatoes clean, then pierce them a few times with a fork. Bake directly on the rack for 45–55 minutes, until they are tender and can be easily pierced with a knife.
While the potatoes bake, in a bowl stir together the shredded chicken with the buffalo sauce until the meat is coated and glossy. If you like it milder, start with 1/3 cup and adjust to taste.
Once the potatoes are done, let them rest for 5 minutes. Carefully slice each potato in half lengthwise, being mindful of steam. Gently scoop a bit of the flesh into a separate bowl to create a bed for the filling, leaving the skins intact.
In the bowl with the potato flesh, mash lightly and mix in salt, pepper, and a touch of ranch or blue cheese dressing to create a creamy base.
Fold the buffalo chicken into the mashed potato mixture. If you prefer extra texture, reserve a small portion of the chicken to sprinkle on top later.
Pile the buffalo chicken mixture back into the hollowed potatoes. Top with shredded cheese and return to the oven for 6–8 minutes, until the cheese is melted and bubbly.
Remove from the oven and drizzle with additional dressing if desired. Finish with chopped celery and green onions for brightness and crunch.
Serve warm, with optional extra hot sauce on the side for those who like more kick. These stuffed potatoes pair nicely with a light salad or steamed greens.