Bring a large pot of water to a boil and add rice noodles. Cook according to package directions, then drain into a colander and rinse thoroughly with cold water. Set aside.

Stir soy sauce, vinegar, maple syrup or agave, garlic, ginger, and white pepper, if using, together in a small bowl.

Cut the tofu into short strips, about 1 inch long and ½ inch thick.

Coat the bottom of a large nonstick skillet with sesame oil and place over medium heat. When oil is hot, add tofu to skillet in an even layer. Cook for about 10 to 12 minutes, flipping once or twice, until tofu is browned on multiple sides. Remove from skillet and transfer to a paper towel-lined plate.

Add vegetable oil to the skillet and raise the heat to medium-high. When oil is hot, ad onion and sauté until softened and lightly browned, about 3 minutes. Raise heat to high and add carrots. Stir-fry for about 3 minutes, until carrots begin to brighten in color a bit. Add snow peas and continue to stir fry until carrots and snow peas are tender-crisp, about 3 minutes more. Add noodles, soy sauce mixture, scallions and tofu to the skillet. Gently toss to coat noodles and veggies in the sauce. Cook just until noodles are heated throughout, about 1 minute. Remove from heat, add bean sprouts and cilantro, and toss a few more times to incorporate.

Divide onto plates and serve. Sprinkle with additional bean sprouts and cilantro, if desired.