Preheat oven to 400 degrees.
Prepare a baking sheet with parchment paper, foil, or a silicone mat.
Slice peppers, tomatoes, onion, and garlic in half. Remove seeds from tomatoes and peppers. Wrap the garlic in foil. Arrange peppers, tomatoes, garlic, and onion on the baking sheet.
Drizzle the prepared vegetables with olive oil and sprinkle the salt and pepper.
Roast for 45-50 minutes until slightly charred.
While the veggies are roasting, boil and cook your pasta according to the package directions.
Once the veggies are roasted, add them to a blender along with their roasting juices and fresh basil. Squeeze the garlic cloves into the blender. Blend until smooth.
Heat the blended veggies over medium heat and add the soy milk, onion powder, garlic powder, and sugar. Taste and adjust seasoning as needed. Add additional milk to thin the sauce if it's too thick.
Add the drained and cooked pasta to the sauce and toss well. Serve warm with grated vegan parmesan and chopped basil.
Store leftovers in a covered container in the fridge for 4-5 days.