Preheat and prep the squash. Heat the oven to 400°F (200°C). Carefully slice the spaghetti squash in half lengthwise and scoop out the seeds. Drizzle the cut sides with a little olive oil, and season with salt and pepper.

Roast until tender. Place the squash halves cut side down on a parchment-lined baking sheet. Roast for 35–45 minutes, or until the flesh is tender and easily shreds with a fork.

Shred the “noodles.” Let the squash cool for 5 minutes. Use a fork to scrape the flesh into spaghetti-like strands, leaving a 1/4-inch border so the shells stay sturdy. Keep the strands inside each shell if possible; otherwise, transfer to a bowl and return later.

Make the buffalo ranch sauce. In a skillet over medium heat, melt the butter. Add the garlic and cook for 30 seconds until fragrant. Stir in the buffalo sauce, ranch dressing, cream cheese, onion powder, smoked paprika, and a pinch of black pepper. Whisk until smooth and creamy, about 2–3 minutes.

Combine with chicken and cheeses. Stir the shredded chicken into the sauce. Fold in half the mozzarella and half the cheddar until everything is coated and melty.

Toss with spaghetti squash. Add the squash strands to the skillet (or pour the sauce mixture into a large bowl with the squash). Toss gently until the strands are fully coated. Taste and adjust salt and pepper as needed.

Stuff the boats. Return the mixture to the spaghetti squash shells, dividing evenly. Top with the remaining mozzarella and cheddar. If using blue cheese, sprinkle a small amount on top for extra bite.

Bake to finish. Return the boats to the oven and bake for 10–12 minutes, until the cheese is melted and bubbling. For a golden top, broil on high for 1–2 minutes, watching closely.

Garnish and serve. Remove from the oven and rest for 5 minutes. Top with chopped green onions and parsley. Drizzle with a little extra ranch or buffalo sauce if you like more sauciness.