Bring a large pot of water to a boil and add the rice noodles. Cook them according to the package directions, then drain them into a colander and rinse thoroughly with cold water.
While the noodles cook, stir the soy sauce, dark soy sauce, vegan oyster sauce, rice vinegar, brown sugar, toasted sesame oil, and white pepper together in a small bowl. Set this aside.
Place a large wok or skillet over medium heat and coat the bottom with 1 tablespoon of the oil. Give the oil a minute to heat up, then add the tofu pieces, arranging them in a single layer (cook them in batches if they won't all fit). Cook the tofu for about 10 minutes, flipping the pieces once or twice, until golden brown. Transfer the tofu to a plate when done.
Add the remaining oil to the wok or skillet and raise the heat to medium-high. Let the oil heat up for a minute, then add the onion. Cook the onion for about 3 minutes, stirring constantly, until it softens and begins to brown.
Add the sugar snap peas and carrots. Stir-fry the mixture for 2 to 3 minutes, until the vegetables are tender-crisp and have intensified in color.
Push the vegetables to the side, then add the garlic and ginger. Sauté the aromatics for about 30 seconds, stirring constantly.
Stir the aromatics in with the vegetables, then add the noodles and cooked tofu to the wok or skillet. Carefully pour the sauce over the noodles. Stir-fry everything for 1 to 2 minutes, until the sauce thickens and coats the noodles, vegetables, and tofu.
Remove the wok or skillet from heat, then stir in the bean sprouts, cilantro, and scallions.
Divide onto plates and serve.