Preheat the oven to 400°F (200°C).

Cut the spaghetti squash in half lengthwise using a sharp knife.

Scoop out the seeds and stringy insides from each half.

Drizzle olive oil, and sprinkle salt and pepper on the cut sides of the squash.

Place them cut-side down on a baking sheet lined with parchment paper and roast for about 30-35 minutes.

While the squash roasts, mix the cooked ground turkey, marinara sauce, Italian seasoning, and half of the mozzarella and Parmesan cheese in a mixing bowl.

Once the squash is tender, remove it from the oven and let it cool slightly.

Scrape the flesh of the squash into strands with a fork.

Mix the scraped squash strands into the turkey filling until well combined.

Fill each half of the squash with the mixture, packing it in tightly.

Top each stuffed squash half with the remaining mozzarella and Parmesan cheese.

Return to the oven and bake for an additional 10-15 minutes until the cheese is bubbly and golden.