In a large skillet over medium-low heat, combine olive oil and vegan butter.
Add thinly sliced onions and sprinkle with salt. Cook for 35-40 minutes, stirring every 4-5 minutes, until golden brown.
Once the onions are caramelized, add minced garlic and sun-dried tomatoes. Cook for another 3-4 minutes.
Incorporate chili crunch oil and assorted herbs into the skillet. Stir to blend flavors.
Pour in low sodium soy sauce and balsamic vinegar, scraping the bottom of the pan.
Gently stir in canned coconut milk and simmer for another 3-4 minutes.
While the sauce simmers, cook spaghetti noodles according to package instructions. Add to the skillet with vegan parmesan and mix well.
Serve hot, topped with extra vegan parmesan, chili crunch oil, and freshly chopped parsley.