Begin by preheating oven to 400ºF.
Next, place cashews into a large bowl and bring 2 cups of water to a boil and pour water over the cashews. Let sit for at least 15 minutes.
Prepare head of garlic by chopping off one end and placing on a piece of tin foil. Generously drizzle with olive oil and then wrap with the tin foil, removing as much air as possible. Roast at 400ºF for 30 minutes.
While your garlic is roasting, prepare vegetables. Spray a large baking dish with nonstick cooking spray and add in chopped mushrooms and spinach. Drizzle with 2 teaspoons of olive oil and season with salt. Bake at 400ºF for 20 minutes. Stirring every 5 minutes.
Before preparing your white wine sauce boil pasta. Bring a large pot of water to a boil and add pasta. Let cook for 3-4 minutes or until pasta is a little crunchier than al dente. It will finish baking in the oven. Strain and set aside.
Prepare white wine pasta sauce by placing 1 cup of dry white wine and 1/2 chopped white onion in a small saucepan. Turn heat to high and bring to a boil. Then, turn to low and let simmer for about 15 minutes or until it reduces by half.
Next, transfer white wine and onion mixture into a high-speed blender. Once your roasted garlic is done cooking, remove it from the tin foil and squeeze roasted garlic cloves into the high-speed blender.
Add the rest of the white wine pasta sauce ingredients and blend on high for at least 60 seconds or until pureed.
Finally, add cooked pasta and vegan pasta sauce to the casserole dish with veggies still inside. Mix well until all ingredients are combined and covered with pasta sauce. Place into the oven and bake for 15-20 minutes or until pasta bake is hot.
Remove from oven and serve.