How to Make It
Preheat oven to 400˚F. Cut squash in half lengthwise; discard seeds. Coat squash evenly with 2 tablespoons of the oil. Place cut side down on a rimmed baking sheet. Bake in preheated oven until tender, 35 to 40 minutes. Remove squash from oven, and flip over. Let stand 15 minutes to cool. Turn off oven, and turn broiler to HIGH.
Stir together hot sauce, butter, vinegar, and Worcestershire in a small saucepan. Bring to a simmer over medium, stirring to melt butter. Remove from heat, and stir in cream cheese until melted and smooth. Stir together sauce mixture, chicken, celery, carrot, scallions, and 1 cup of the cheese in a large bowl.
Gently scrape interior of squash from edges, and place in a medium bowl. Separate cooled squash into strands with forks. Sprinkle with salt and pepper. Add squash strands to chicken mixture; gently toss to swirl together, but do not over mix.
Place squash halves, cut-side up, on a parchment-lined baking sheet. Divide mixture evenly among squash shells; sprinkle with remaining 1 cup cheese. Bake in preheated oven until cheese is melted and lightly browned, about 4 minutes. Sprinkle with scallions and blue cheese crumbles. Drizzle with ranch dressing, if desired.