Preheat and prep: Heat the oven to 400°F (205°C). Line a baking sheet with parchment for easy cleanup.

Cut the squash safely: Trim the ends, then slice the squash in half lengthwise. Scoop out the seeds with a spoon.

Roast the squash: Rub cut sides with 1 tablespoon olive oil. Season with salt and pepper. Place cut-side down on the sheet and roast 35–45 minutes, until the flesh is easily shredded with a fork but not mushy.

Cool and shred: Let the squash rest 5–10 minutes. Use a fork to pull the strands into “spaghetti.” Pat the strands with paper towels to remove extra moisture.

Sauté aromatics: In a skillet, warm 1 tablespoon olive oil over medium heat. Add garlic and cook 30–60 seconds until fragrant. Stir in Italian seasoning, onion powder, and red pepper flakes if using.

Build the sauce: Pour in the marinara and warm through. Taste and season with salt and pepper. You want a well-seasoned, slightly thick sauce.

Combine the base: In a large bowl, mix the squash strands, shredded chicken, and about 1 cup of the mozzarella with half the Parmesan. Add the marinara and toss until everything is well coated.

Assemble the bake: Spread the mixture into a lightly greased 9x13-inch baking dish. Top with the remaining mozzarella and Parmesan.

Bake to bubbly: Lower oven to 375°F (190°C). Bake 20–25 minutes until the edges are bubbling and the cheese is melted and golden.

Finish and rest: Let it sit 10 minutes so it sets and slices cleanly. Garnish with chopped basil or parsley before serving.