Preheat your oven to 400°F (200°C). Cut the spaghetti squash in half lengthwise, scoop out seeds, drizzle with olive oil, and season with salt and pepper. Roast cut-side down on a baking sheet for 30-40 minutes until tender.
While baking the squash, heat olive oil in a skillet over medium heat. Season chicken with salt, pepper, and garlic powder. Cook for 5-7 minutes per side until done. Remove to rest and slice thinly.
In the same skillet, melt butter over medium heat. Add minced garlic and sauté. Pour in heavy cream, bring to a simmer, add Parmesan, and stir until sauce is thick.
Scrape squash with a fork to create strands. Fill each half with sliced chicken and pour Alfredo sauce. Bake in oven another 5-10 minutes.
Garnish with parsley and serve the squash boats warm.
Notes
Store unused boats in the fridge for up to 3 days and reheat in the oven for best results.