Preheat oven to 375°F and line a large baking sheet with parchment paper or silicone baking mat.
Drizzle two tablespoons of the olive oil on the cut side of each squash half. Season with salt and pepper then place cut side down on the baking sheet. Bake for about 40 minutes until squash is tender enough to shred the strands but not collapsing in on itself.
While squash bakes, combine the artichokes, spinach, 1 cup pecorino romano, sun-dried tomatoes, tomato sauce and remaining two tablespoons olive oil in a large bowl. Add the salt, pepper, garlic powder and nutmeg.
Remove the squash when done baking and let cool long enough to handle. Scrape the center of each squash half into the bowl with the filling leaving enough squash intact around the perimeter of the squash half so that it maintains its shape.
Once all the spaghetti squash centers have been added to the bowl with the filling, stir everything together until well combined.
Spoon the mixture back into each hollowed squash half.
Sprinkle the remaining 1/4 cup cheese evenly among the squash and top with the breadcrumbs.
Spray the tops of each squash with an olive oil baking spray (or drizzle lightly with olive oil if you don't have baking spray) then place back in the oven at 375°F for 10 minutes.
Turn the oven to broil for 2-3 minutes at the end watching carefully so breadcrumbs don't burn.
Serve hot and enjoy!
Notes
*I prefer pecorino romano to parmesan as it's a sheep's milk cheese rather than cow. Feel free to substitute parmesan in this recipe if preferred.**You can easily make your own gluten-free breadcrumbs using any gluten-free bread you have on hand. For this recipe, toast one slice of bread. Let cool then blitz in a food processor or blender until breadcrumb size.