Combine oat milk, nutritional yeast, and flour in a blender.
Blend until smooth, and set aside.
Cook pasta according to package directions in a separate pan.
In a pot, saute onions and garlic until the onions are translucent.
Then add mushrooms (if using) and cook until browned.
Add crushed tomatoes, Italian seasoning, red pepper flakes, salt, pepper, and white wine.
Stir and heat on medium until the tomato mixture begins to boil.
Then, whisk in the creamy plant-milk mixture, and reduce heat to low.
The sauce will thicken as it cooks.
When the pasta is done cooking, drain it in a colander, and add it to the creamy tomato sauce.
Now turn the heat off, and stir the pasta into the sauce.
Add the chopped basil and vegan parmesan cheese.
I suggest serving with an Italian Salad and crusty bread.