Preheat the oven to 400F and grease a baking dish with olive oil or cooking spray.
Wash the spaghetti squash, dry the skin completely, and cut it in halves. With a fork, pierce the skin of the squash 6 to 7 times to ensure even cooking.
Drizzle olive oil onto the flesh of each squash half and season with salt and pepper.
Bake:
Place each half flesh-side down into the baking dish and bake for 30 to 40 minutes or until the flesh is tender.
Serve:
Once the spaghetti squash is fork-tender, shred the squash meat into a large serving bowl.
Top with butter, garlic powder, 2 tablespoons Parmesan cheese, salt, and black pepper. Toss to combine, serve, and top with parsley and remaining Parmesan cheese.