Prepare the Spaghetti Squash:

1. Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
2. Slice each spaghetti squash in half lengthwise and scoop out the seeds.
3. Drizzle the cut sides with olive oil and season with salt and pepper.
4. Place squash halves cut side down on the baking sheet and roast for 30–40 minutes, or until tender and easily pierced with a fork.

2. Cook the Sausage and Mushrooms:

1. Heat 1 tablespoon of olive oil in a large skillet over medium heat.
2. Add the crumbled sausage and sliced mushrooms. Cook for 5 minutes, stirring occasionally, until the sausage is browned and fully cooked.
3. Drain any excess fat from the skillet.

3. Add Aromatics and Vegetables:

1. Stir in minced garlic, Italian seasoning, and red pepper flakes (if using).
2. Add half the cherry tomatoes and cook for 2–3 minutes until softened.
3. Gradually add spinach, stirring until wilted.

4. Prepare the Squash for Stuffing:

1. Remove the roasted squash from the oven and let it cool slightly.
2. Use a fork to scrape and loosen the spaghetti-like strands inside the squash shells, leaving them in place to create a base for the stuffing.

5. Assemble and Bake:

1. Divide the sausage mixture evenly among the squash halves, stuffing them generously.
2. Top each half with the remaining cherry tomatoes and shredded Parmesan cheese.
3. Return the squash to the oven and bake for 15 minutes, or until the cheese is melted and bubbly.

6. Garnish and Serve:

1. Remove from the oven and garnish with fresh thyme and additional Parmesan cheese if desired.
2. Serve warm, drizzling with extra olive oil for added richness.