Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper. Cut the spaghetti squash in half lengthwise, scoop out the seeds, drizzle the insides with olive oil, and sprinkle with salt and pepper. Place cut-side down on the baking sheet and roast for 30-40 minutes until tender.

In a medium mixing bowl, combine the shredded cooked chicken with buffalo sauce and mix well. Then, add the cream cheese and stir until creamy.

Fold in the shredded mozzarella and cheddar cheese until evenly distributed in the filling mixture.

Turn the insides of roasted spaghetti squash into strands with a fork. Gently scoop the chicken filling into each half, letting it overflow slightly.

Return the stuffed squash to the oven and bake for an additional 15-20 minutes until the cheese is melted and bubbling.

Remove from the oven, let cool for a few minutes, and top with sliced green onions and ranch dressing before serving.