Pre-heat oven to 400 degrees.
Cut spaghetti squash in half lengthwise and scoop out seeds. Rub with olive oil if desired and season with 1 tsp Italian seasoning. Place on a baking sheet, cut side up, and bake for 35-40 minutes or until flesh flakes apart easily with a fork.
Add ground chicken, sausage, breadcrumbs, and egg whites to a bowl. Mix with hands until combined, then form into 1 1/2" meatballs. Set aside.
Heat a large, oven-safe pan over medium-high heat. Add olive oil until hot, then add onion and garlic. Sauté until fragrant, then add crushed tomatoes, coconut milk, and 1 tsp Italian seasoning.
Add meatballs to sauce, cover meatballs in sauce, then bake at 400 degrees for 20-25 minutes or until cooked through.
Cook butternut squash noodles as desired - I steamed them in the microwave for about 4 minutes. Layer spaghetti squash and butternut squash noodles in the bottom of 5 containers. Top with meatballs and sauce.