Preheat the oven to 375 degrees.
Carefully cut the spaghetti squash in half and remove the seeds. Place the squash upside down on a baking sheet and roast for about 30 minutes.
While the squash is roasting, start making the mushroom sauce. I mostly followed Emily Malone's recipe.
Slice and saute 1 package of mushrooms. Cook the mushrooms for 5 to 10 minutes.
Add 1 cup of almond milk. Bring the sauce to a simmer and let it cook down a bit. Stir frequently.
Add 2 tablespoons of nutritional yeast (a great source of B12!). Add one more cup of almond milk. Keep stirring. I left out the creamer and cornstarch from Emily Malone's recipe because I didn't have any. I instead added a bit of flour to thicken up the sauce. After the sauce has thickened, add salt and pepper to taste and get ready to pour.
Once the squash is cooked, use a fork to pull the flesh out in strands. Serve the spaghetti squash with a big spoonful of mushroom sauce on top! :)