Bring salted water to a boil and cook pasta for 1-2 minutes less than package instructions.
In another large pot, melt vegan butter over medium heat. Add diced onion and sauté for 5-7 minutes until soft and slightly browned.
Add minced garlic and diced carrots, sauté for an additional 5 minutes.
Add peas and corn, sauté for 1-2 minutes.
Stir in vegetable broth, cashew cream, nutritional yeast, gluten-free flour, salt, pepper, and thyme. Whisk until smooth and fully incorporated.
Bring the mixture to a low boil, then reduce to simmer and cook for about 5 minutes, or until it thickens.
Add the al dente pasta and let everything simmer for another 5 minutes to allow the flavors to meld.
Taste and adjust seasonings with additional salt, pepper, or other seasonings as needed.
Serve, garnished with fresh parsley and a sprinkle of red pepper flakes.