Mix the mozzarella, fontina, and provolone and divide in half.
Mix half of the shredded cheese mixture with the parmesan, ricotta, cream, spinach, garlic, and thyme before seasoning with salt and pepper to taste.
Divide the cheese and spinach mixture between the spaghetti squash, placing it in the hollowed out centers where the seeds used to be, before sprinkling on the remaining mixture of the shredded cheeses.
Roast in a preheated 400F/200C oven until the spaghetti squash is tender, the cheese has melted and is bubbling, about 30-40 minutes.
Either serve as is in the shells, or shred the spaghetti squash into ‘noodles’, mixing it in with all of the melted cheese and serve in the shells or in a bowl.
