Heat a large skillet over medium heat and add 2 tablespoons of olive oil. Once shimmering, add the finely chopped onion and sauté until it becomes translucent and fragrant, about 3-4 minutes.
Add the minced garlic to the skillet and cook for another minute, stirring constantly, until it releases a sweet, pungent aroma without browning.
Pour in the canned fire-roasted tomatoes, breaking them apart with your spoon if whole. Stir in salt, pepper, and sugar if using, then bring to a gentle simmer. Let this simmer uncovered for 15-20 minutes, stirring occasionally, until the sauce thickens slightly and deepens in color.
Meanwhile, cook your pasta in boiling salted water until al dente, following package instructions—usually about 8-10 minutes. Drain the pasta, reserving a cup of pasta water for adjusting the sauce later.
Stir the cooked pasta into the tomato sauce, tossing well to coat each strand evenly. If the sauce feels too thick, loosen it with a splash of the reserved pasta water, stirring gently to combine.
Pour in the plant-based milk and stir until the sauce becomes extra creamy and velvety. Taste and adjust seasonings as needed. Finish by folding in fresh basil for a burst of aroma and brightness.
Cook for another 2 minutes, allowing the flavors to meld and the basil to wilt slightly. The sauce should be vibrant red, fragrant, and cling to the pasta with a smooth, velvety texture.
Serve hot, garnished with additional basil if desired, and enjoy the comforting, rich flavors of this simple vegan pasta.