• Preheat the oven to 400℉
• Drizzle the cut sides of the spaghetti squash with olive oil, and sprinkle with salt and pepper.
• Place the squash halves cut-side down on a baking sheet. Roast for 35-40 minutes or until the flesh is tender and easily scraped with a fork to form "spaghetti-like" strands.

Cook the ground beef.

• While the squash is roasting, heat olive oil in a skillet over medium heat.

  Add minced garlic and sauté for 1-2 minutes.
• Add the beef and cook until browned, breaking it up as it cooks.
• Season with salt and pepper.
• Stir in the marinara sauce and let it simmer for 5-7 minutes until heated through.
• Fill each spaghetti squash half with the beef marinara mixture.
• Sprinkle with mozzarella and Parmesan cheese.
• Return the filled squash boats to the oven and bake for an additional 10 minutes, or until the cheese is melted and bubbly.
• Remove from the oven and garnish with chopped parsley if desired.