Begin by preheating oven to 400 degrees. Wash and rinse a spaghetti squash, cut it in half length wise, and then scoop out the seeds from the center of both halves. Place halves of squash flesh side down in a 9X13 pan sprayed with cooking spray. Bake for 45-50 minutes, or until tender.
Once spaghetti squash is tender, use a fork to pull out strands of the flesh. Remove as much flesh as possible from both halves and place them in a bowl. Mix strands of spaghetti squash with spaghetti sauce from the jar until they are coated. I did not use the whole jar, just 470 g. Add sauce according to your taste preference, but keep in mind that the more sauce, the runnier your casserole may be.
Brown turkey, onion, and garlic together in a pan over medium-high heat, until the turkey is cooked through. Crumble the turkey as it cooks. Add in 3 teaspoons of Italian seasoning and garlic salt to taste. Drain off any excess liquid from the pan. Add 1 whole jar of spaghetti sauce to the skillet and stir to combine. Turn off heat and set aside.
In a mixing bowl, combine softened cream cheese, cottage cheese, sour cream, 3/4 cup of mozzarella cheese (84 g), and 1 tsp of Italian seasoning until thoroughly combined.
Preheat the oven to 350 degrees. Spray a 9X13 pan with cooking spray. Place the spaghetti squash evenly in the bottom of the pan. Layer on the cream cheese mixture evenly over the spaghetti squash. Pour turkey/spaghetti sauce over the cream cheese layer. Top with remaining mozzarella cheese (112 g).
Bake in a preheated oven for about 35-45 minutes, or until hot and bubbly. Allow to rest for about 10 minutes before serving.