Place the rice noodles in a large bowl and cover with very hot tap water. Let them soak until they are pliable but still have a firm, slightly al dente core, about 20 to 30 minutes, then drain well.

Pulse the chiles, garlic, and shallots in a food processor until they form a coarse paste, scraping down the sides as needed.

Whisk the vegetable broth, fish sauce substitute, brown sugar, and lime juice together in a medium bowl until the sugar dissolves.

Pat the tofu dry with paper towels and toss with salt, pepper, and cornstarch in a large bowl until evenly coated. Heat a portion of the vegetable oil in a large nonstick skillet or wok over medium-high heat until the oil should shimmer but not smoke.

Add the tofu to the skillet and cook, turning occasionally, until golden brown and crispy on all sides, about 8 to 10 minutes. Transfer the tofu to a paper towel-lined plate and wipe out the skillet.

Heat the remaining oil in the same skillet over medium-high heat. Add the chile paste and cook until fragrant and just starting to brown, about 1 to 2 minutes.

Add the snap peas and bell pepper. Stir-fry until the vegetables are bright and crisp-tender, about 2 to 3 minutes.

Pour in the broth mixture and add the drained noodles. Cook, tossing constantly, until the noodles have absorbed most of the sauce and are fully tender, 3 to 5 minutes.

Remove the skillet from the heat. Fold in the crispy tofu and basil leaves until the basil is just wilted. Serve immediately, while the tofu is still crispy.