Grease a 9 x 13-inch baking dish lightly with coconut oil and set aside. Pre-heat oven to 350 degrees F. (I usually do this when I'm about the assemble the layers, see note below)
Spaghetti Squash ("Pasta") Layer
Cut the spaghetti squash in half lengthwise (see note for softening in the microwave first), and scoop out the seeds.
If using an Instant Pot, place the steamer insert inside the pot and pour in 1 cup of water. Place the cut and seeded halves of the squash on the insert, close the lid and make sure the valve is closed. Set to "MANUAL" for 7 minutes. Once done, turn off the cooking and quick-release by carefully using a wooden spoon to turn the top valve to “venting.” See notes.
If not using an Instant Pot, lightly oil the cut squash halves and place them on a baking sheet at 375 degrees F for approx. 30-35 minutes facing down. You want the squash cooked enough to remove the threads, but al dente enough not to over-cook during the baking step.
When done, set aside and let cool.
Ground Meat Layer
Heat the pan on medium and cook the ground meat, breaking it up into small pieces, until all the pink color is gone. Remove the cooked meat to a bowl.
Return the pan to medium heat and add a little oil. Add the onions to the pan and stir them for 3-5 minutes until translucent and soft. Stir in the garlic and cook until fragrant, 1 minute more.
Stir in the tomato paste and let it cook for 2 minutes to release the flavor without letting it burn.
Return the ground meat to the pot and stir. Add the herbs and other seasonings and mix well.
Taste the meat mixture and season to your liking, then set aside.
Cauliflower "Cream" Sauce
In a pot with a steamer insert, steam cauliflower florets until tender when pricked with a fork (10-15 minutes). When it's done, remove from the heat.
Meanwhile, heat the coconut cream in a saucepan over low heat until the creamy parts dissolve. Add the nutritional yeast and stir, using a wooden spoon, until mixed.
While that cooks, stir the arrowroot flour into the water until it creates a slurry with no clumps at the bottom. Once that's mixed well, pour it into the pot of coconut cream. Continue to stir the mixture.
Bring the sauce to a simmer, and cook until the sauce is thick enough to coat your spoon. Turn heat off.
Add the cooled cauliflower to a high-speed blender (I use a Vitamix) with the lemon juice and salt. Pour the cream sauce over it and blend on high until everything is mixed well and smooth, about 30-40 seconds. Taste and add salt as desired, set aside.
Stir together the topping for the very end: mix 2 tablespoons nutritional yeast with 1-2 teaspoons of cinnamon and the sea salt in a bowl. Chop your parsley and place in another small bowl. Set aside.
Assemble the layers and bake
I usually preheat the oven to 350 degrees F now.
Add two-thirds of your spaghetti squash evenly to the bottom of your greased baking dish.
Spread the ground meat mixture on top of that.
Pour two-thirds of your cauliflower-cream sauce over the meat and spread it to cover the meat evenly.
Now, pull the remaining “threads” out of the squash onto the sauce-covered surface in forkfuls.
Spread the remaining "cream" sauce over the top.
Sprinkle your nutritional yeast-cinnamon topping lightly and evenly over the whole dish. Sprinkle with chopped parsley, if desired
Bake for 40 minutes until the top is golden-brown and the edges are bubbling. Let rest for 5-10 minutes before cutting into it. Enjoy! This will keep well in the fridge for a week.