Cut the spaghetti squash in half lengthwise and remove the seeds.
Drizzle oil over the inside of the squash halves and season with salt and pepper.
Place them on a baking sheet, cut side down, and poke some holes in the shells with a fork.
Bake for 30-35 minutes.
Chicken: Heat oil in a large skillet on medium heat, and, when it's hot, place the chicken breasts in the pan. Season the chicken with the salt, pepper, and spices.
Cook the chicken undisturbed for 7-8 minutes until the bottom is starting to turn brown.
Flip it over and add butter to the skillet. Cook for another 7-8 minutes until it's fully cooked and then transfer the chicken to a cutting board to rest.
Sauce: Turn the skillet down to medium-low heat and add the butter, cream, minced garlic, spices, salt, and pepper. Whisk until the butter is melted and the mixture is smooth.
Bring the sauce to a slow simmer, and cook for 3-5 minutes until it's starting to thicken, whisking frequently.
Add the shredded parmesan cheese and whisk until it's completely melted.
Assemble: When the squash is done, using two forks, scrape the squash "noodles" out of the shells.
Place the squash in a bowl and stir in the sauce. Then evenly divide the squash between the spaghetti squash shells.
Slice the chicken and neatly arrange it on top of the squash.
Notes
You can substitute milk for the heavy cream, but the sauce won't be as rich and creamy.