Preheat the oven to 425 degrees F. Line a baking sheet with foil and spray with nonstick spray.
Slice the spaghetti squash in half lengthwise and scrape out the sides. Brush the cut sides with olive oil. Place the squash cut-side down on a baking sheet. Roast for 25 minutes.
While the squash is roasting, make the chicken. Heat a large skillet over medium heat and add the butter. Sprinkle the chicken all over with salt and pepper. Place it in the skillet and brown on all sides, cooking through, about 5 to 6 minutes. Reduce the heat to low and drizzle in the 1/3 cup buffalo wing sauce. Sprinkle in half of the sliced scallions. Toss to coat then turn off the heat.
When the squash are done, remove the baking sheet and flip the squash over. Use a fork to scrape some of the squash up. Season the squash with a pinch of salt and pepper. Drizzle on some buffalo wing sauce and blue cheese dressing or ranch, if you wish. Sprinkle on a little bit of cheddar. Next, layer on the chicken and divide the pieces evenly between the squash.
Top with the remaining cheddar and the blue cheese. Place back in the oven and cook for another 15 minutes, until all the cheese is bubbly and warm.
Remove the squash from the oven. Stir together the remaining green onions, cilantro and chives. Sprinkle them all over the squash. Drizzle with more wing sauce if you'd like and top with crumbled blue cheese if you wish. Serve!
These are delish for lunch/dinner leftovers too. I simply wrap the entire squash in foil and refrigerate. Then I reheat in a low oven (like 300 degrees) for 20 minutes or so until warm.